I was autogenerating some speed tiers for
Hoenn Gaiden, when I noticed I could do it for [Gen 3] OU, too: this gives you an idea of what outspeeds what, given either max Speed (+ Nature), max Speed (neutral Nature), or 0 EVs. It isn't meant to be comprehensive in the slightest (and we all know 252+ +2 Jolteon isn't a notable benchmark by any means :P).
788, Jolteon (252+ +2) (Agility)
788, Aerodactyl (252+ +2) (Agility)
766, Swellow (252+ +2) (Agility)
744, Sceptile (252+ +2) (Agility)
718, Jolteon (252 +2) (Agility)
718, Aerodactyl (252 +2) (Agility)
700, Dodrio (252+ +2) (Agility)
698, Swellow (252 +2) (Agility)
678, Sceptile (252 +2) (Agility)
656, Charizard (252+ +2) (Dragon Dance)
656, Zapdos (252+ +2) (Agility)
656, Salamence (252+ +2) (Dragon Dance)
638, Dodrio (252 +2) (Agility)
612, Moltres (252+ +2) (Agility)
598, Charizard (252 +2) (Dragon Dance)
598, Zapdos (252 +2) (Agility)
598, Salamence (252 +2) (Dragon Dance)
591, Jolteon (252+ +1) (Salac Berry)
591, Aerodactyl (252+ +1) (Salac Berry)
591, Crobat (252+ +1) (Salac Berry)
590, Articuno (252+ +2) (Agility)
590, Kingdra (252+ +2) (Agility, Dragon Dance)
574, Gyarados (252+ +2) (Dragon Dance)
574, Swellow (252+ +1) (Salac Berry)
568, Dragonite (252+ +2) (Agility, Dragon Dance)
558, Moltres (252 +2) (Agility)
558, Dugtrio (252+ +1) (Salac Berry)
558, Alakazam (252+ +1) (Salac Berry)
558, Sceptile (252+ +1) (Salac Berry)
541, Starmie (252+ +1) (Salac Berry)
541, Raikou (252+ +1) (Salac Berry)
538, Articuno (252 +2) (Agility)
538, Kingdra (252 +2) (Agility, Dragon Dance)
538, Jolteon (252 +1) (Salac Berry)
538, Aerodactyl (252 +1) (Salac Berry)
538, Crobat (252 +1) (Salac Berry)
525, Dodrio (252+ +1) (Salac Berry)
525, Gengar (252+ +1) (Salac Berry)
525, Tauros (252+ +1) (Salac Berry)
525, Jumpluff (252+ +1) (Salac Berry)
525, Espeon (252+ +1) (Salac Berry)
524, Skarmory (252+ +2) (Agility)
524, Metagross (252+ +2) (Agility)
523, Swellow (252 +1) (Salac Berry)
522, Gyarados (252 +2) (Dragon Dance)
518, Dragonite (252 +2) (Agility, Dragon Dance)
508, Dugtrio (252 +1) (Salac Berry)
508, Alakazam (252 +1) (Salac Berry)
508, Sceptile (252 +1) (Salac Berry)
508, Kadabra (252+ +1) (Salac Berry)
502, Scizor (252+ +2) (Agility)
493, Starmie (252 +1) (Salac Berry)
493, Raikou (252 +1) (Salac Berry)
492, Charizard (252+ +1) (Dragon Dance, Salac Berry)
492, Zapdos (252+ +1) (Salac Berry)
492, Typhlosion (252+ +1) (Salac Berry)
492, Miltank (252+ +1) (Salac Berry)
492, Entei (252+ +1) (Salac Berry)
492, Celebi (252+ +1) (Salac Berry)
492, Slaking (252+ +1) (Salac Berry)
492, Flygon (252+ +1) (Salac Berry)
492, Salamence (252+ +1) (Dragon Dance, Salac Berry)
492, Jirachi (252+ +1) (Salac Berry)
486, Tyranitar (252+ +2) (Dragon Dance)
480, Lapras (252+ +2) (Dragon Dance)
480, Porygon2 (252+ +2) (Agility)
478, Skarmory (252 +2) (Agility)
478, Metagross (252 +2) (Agility)
478, Dodrio (252 +1) (Salac Berry)
478, Gengar (252 +1) (Salac Berry)
478, Tauros (252 +1) (Salac Berry)
478, Jumpluff (252 +1) (Salac Berry)
478, Espeon (252 +1) (Salac Berry)
475, Jynx (252+ +1) (Salac Berry)
475, Houndoom (252+ +1) (Salac Berry)
463, Kadabra (252 +1) (Salac Berry)
459, Moltres (252+ +1) (Salac Berry)
459, Zangoose (252+ +1) (Salac Berry)
458, Scizor (252 +2) (Agility)
448, Charizard (252 +1) (Dragon Dance, Salac Berry)
448, Zapdos (252 +1) (Salac Berry)
448, Typhlosion (252 +1) (Salac Berry)
448, Miltank (252 +1) (Salac Berry)
448, Entei (252 +1) (Salac Berry)
448, Celebi (252 +1) (Salac Berry)
448, Slaking (252 +1) (Salac Berry)
448, Flygon (252 +1) (Salac Berry)
448, Salamence (252 +1) (Dragon Dance, Salac Berry)
448, Jirachi (252 +1) (Salac Berry)
442, Tyranitar (252 +2) (Dragon Dance)
442, Articuno (252+ +1) (Salac Berry)
442, Heracross (252+ +1) (Salac Berry)
442, Kingdra (252+ +1) (Dragon Dance, Salac Berry)
442, Suicune (252+ +1) (Salac Berry)
438, Lapras (252 +2) (Dragon Dance)
438, Porygon2 (252 +2) (Agility)
433, Jynx (252 +1) (Salac Berry)
433, Houndoom (252 +1) (Salac Berry)
430, Gyarados (252+ +1) (Dragon Dance, Salac Berry)
430, Milotic (252+ +1) (Salac Berry)
426, Venusaur (252+ +1) (Salac Berry)
426, Dragonite (252+ +1) (Dragon Dance, Salac Berry)
426, Blaziken (252+ +1) (Salac Berry)
426, Gardevoir (252+ +1) (Salac Berry)
426, Medicham (252+ +1) (Salac Berry)
418, Moltres (252 +1) (Salac Berry)
418, Zangoose (252 +1) (Salac Berry)
409, Smeargle (252+ +1) (Salac Berry)
409, Claydol (252+ +1) (Salac Berry)
403, Articuno (252 +1) (Salac Berry)
403, Heracross (252 +1) (Salac Berry)
403, Kingdra (252 +1) (Dragon Dance, Salac Berry)
403, Suicune (252 +1) (Salac Berry)
394, Jolteon (252+)
394, Aerodactyl (252+)
394, Crobat (252+)
393, Magneton (252+ +1) (Salac Berry)
393, Cloyster (252+ +1) (Salac Berry)
393, Skarmory (252+ +1) (Salac Berry)
393, Ludicolo (252+ +1) (Salac Berry)
393, Breloom (252+ +1) (Salac Berry)
393, Metagross (252+ +1) (Salac Berry)
391, Gyarados (252 +1) (Dragon Dance, Salac Berry)
391, Milotic (252 +1) (Salac Berry)
388, Venusaur (252 +1) (Salac Berry)
388, Dragonite (252 +1) (Dragon Dance, Salac Berry)
388, Blaziken (252 +1) (Salac Berry)
388, Gardevoir (252 +1) (Salac Berry)
388, Medicham (252 +1) (Salac Berry)
383, Swellow (252+)
376, Vaporeon (252+ +1) (Salac Berry)
376, Umbreon (252+ +1) (Salac Berry)
376, Scizor (252+ +1) (Salac Berry)
373, Smeargle (252 +1) (Salac Berry)
373, Claydol (252 +1) (Salac Berry)
372, Dugtrio (252+)
372, Alakazam (252+)
372, Sceptile (252+)
364, Tyranitar (252+ +1) (Dragon Dance, Salac Berry)
361, Starmie (252+)
361, Raikou (252+)
360, Weezing (252+ +1) (Salac Berry)
360, Lapras (252+ +1) (Dragon Dance, Salac Berry)
360, Porygon2 (252+ +1) (Salac Berry)
360, Swampert (252+ +1) (Salac Berry)
359, Jolteon (252)
359, Aerodactyl (252)
359, Crobat (252)
358, Magneton (252 +1) (Salac Berry)
358, Cloyster (252 +1) (Salac Berry)
358, Skarmory (252 +1) (Salac Berry)
358, Ludicolo (252 +1) (Salac Berry)
358, Breloom (252 +1) (Salac Berry)
358, Metagross (252 +1) (Salac Berry)
350, Dodrio (252+)
350, Gengar (252+)
350, Tauros (252+)
350, Jumpluff (252+)
350, Espeon (252+)
349, Swellow (252)
343, Vaporeon (252 +1) (Salac Berry)
343, Umbreon (252 +1) (Salac Berry)
343, Scizor (252 +1) (Salac Berry)
343, Machamp (252+ +1) (Salac Berry)
343, Exeggutor (252+ +1) (Salac Berry)
343, Ursaring (252+ +1) (Salac Berry)
343, Blissey (252+ +1) (Salac Berry)
339, Dugtrio (252)
339, Alakazam (252)
339, Sceptile (252)
339, Kadabra (252+)
331, Tyranitar (252 +1) (Dragon Dance, Salac Berry)
329, Starmie (252)
329, Raikou (252)
328, Weezing (252 +1) (Salac Berry)
328, Lapras (252 +1) (Dragon Dance, Salac Berry)
328, Porygon2 (252 +1) (Salac Berry)
328, Swampert (252 +1) (Salac Berry)
328, Charizard (252+)
328, Zapdos (252+)
328, Typhlosion (252+)
328, Miltank (252+)
328, Entei (252+)
328, Celebi (252+)
328, Slaking (252+)
328, Flygon (252+)
328, Salamence (252+)
328, Jirachi (252+)
327, Chansey (252+ +1) (Salac Berry)
327, Donphan (252+ +1) (Salac Berry)
327, Hariyama (252+ +1) (Salac Berry)
327, Regirock (252+ +1) (Salac Berry)
327, Regice (252+ +1) (Salac Berry)
327, Registeel (252+ +1) (Salac Berry)
319, Dodrio (252)
319, Gengar (252)
319, Tauros (252)
319, Jumpluff (252)
319, Espeon (252)
317, Jynx (252+)
317, Houndoom (252+)
313, Machamp (252 +1) (Salac Berry)
313, Exeggutor (252 +1) (Salac Berry)
313, Ursaring (252 +1) (Salac Berry)
313, Blissey (252 +1) (Salac Berry)
310, Marowak (252+ +1) (Salac Berry)
310, Armaldo (252+ +1) (Salac Berry)
309, Kadabra (252)
306, Moltres (252+)
306, Zangoose (252+)
299, Charizard (252)
299, Zapdos (252)
299, Typhlosion (252)
299, Miltank (252)
299, Entei (252)
299, Celebi (252)
299, Slaking (252)
299, Flygon (252)
299, Salamence (252)
299, Jirachi (252)
298, Chansey (252 +1) (Salac Berry)
298, Donphan (252 +1) (Salac Berry)
298, Hariyama (252 +1) (Salac Berry)
298, Regirock (252 +1) (Salac Berry)
298, Regice (252 +1) (Salac Berry)
298, Registeel (252 +1) (Salac Berry)
296, Jolteon (0)
296, Aerodactyl (0)
296, Crobat (0)
295, Articuno (252+)
295, Heracross (252+)
295, Kingdra (252+)
295, Suicune (252+)
294, Rhydon (252+ +1) (Salac Berry)
294, Forretress (252+ +1) (Salac Berry)
289, Jynx (252)
289, Houndoom (252)
287, Gyarados (252+)
287, Milotic (252+)
286, Swellow (0)
284, Venusaur (252+)
284, Dragonite (252+)
284, Blaziken (252+)
284, Gardevoir (252+)
284, Medicham (252+)
283, Marowak (252 +1) (Salac Berry)
283, Armaldo (252 +1) (Salac Berry)
279, Moltres (252)
279, Zangoose (252)
276, Dugtrio (0)
276, Alakazam (0)
276, Sceptile (0)
273, Smeargle (252+)
273, Claydol (252+)
269, Articuno (252)
269, Heracross (252)
269, Kingdra (252)
269, Suicune (252)
268, Rhydon (252 +1) (Salac Berry)
268, Forretress (252 +1) (Salac Berry)
266, Starmie (0)
266, Raikou (0)
262, Magneton (252+)
262, Cloyster (252+)
262, Skarmory (252+)
262, Ludicolo (252+)
262, Breloom (252+)
262, Metagross (252+)
261, Gyarados (252)
261, Milotic (252)
261, Slowbro (252+ +1) (Salac Berry)
261, Snorlax (252+ +1) (Salac Berry)
261, Steelix (252+ +1) (Salac Berry)
259, Venusaur (252)
259, Dragonite (252)
259, Blaziken (252)
259, Gardevoir (252)
259, Medicham (252)
256, Dodrio (0)
256, Gengar (0)
256, Tauros (0)
256, Jumpluff (0)
256, Espeon (0)
251, Vaporeon (252+)
251, Umbreon (252+)
251, Scizor (252+)
249, Smeargle (252)
249, Claydol (252)
246, Kadabra (0)
244, Dusclops (252+ +1) (Salac Berry)
243, Tyranitar (252+)
240, Weezing (252+)
240, Lapras (252+)
240, Porygon2 (252+)
240, Swampert (252+)
239, Magneton (252)
239, Cloyster (252)
239, Skarmory (252)
239, Ludicolo (252)
239, Breloom (252)
239, Metagross (252)
238, Slowbro (252 +1) (Salac Berry)
238, Snorlax (252 +1) (Salac Berry)
238, Steelix (252 +1) (Salac Berry)
236, Charizard (0)
236, Zapdos (0)
236, Typhlosion (0)
236, Miltank (0)
236, Entei (0)
236, Celebi (0)
236, Slaking (0)
236, Flygon (0)
236, Salamence (0)
236, Jirachi (0)
229, Vaporeon (252)
229, Umbreon (252)
229, Scizor (252)
229, Machamp (252+)
229, Exeggutor (252+)
229, Ursaring (252+)
229, Blissey (252+)
226, Jynx (0)
226, Houndoom (0)
223, Dusclops (252 +1) (Salac Berry)
221, Tyranitar (252)
219, Weezing (252)
219, Lapras (252)
219, Porygon2 (252)
219, Swampert (252)
218, Chansey (252+)
218, Donphan (252+)
218, Hariyama (252+)
218, Regirock (252+)
218, Regice (252+)
218, Registeel (252+)
216, Moltres (0)
216, Zangoose (0)
209, Machamp (252)
209, Exeggutor (252)
209, Ursaring (252)
209, Blissey (252)
207, Marowak (252+)
207, Armaldo (252+)
206, Articuno (0)
206, Heracross (0)
206, Kingdra (0)
206, Suicune (0)
199, Chansey (252)
199, Donphan (252)
199, Hariyama (252)
199, Regirock (252)
199, Regice (252)
199, Registeel (252)
198, Gyarados (0)
198, Milotic (0)
196, Venusaur (0)
196, Dragonite (0)
196, Blaziken (0)
196, Gardevoir (0)
196, Medicham (0)
196, Rhydon (252+)
196, Forretress (252+)
189, Marowak (252)
189, Armaldo (252)
186, Smeargle (0)
186, Claydol (0)
179, Rhydon (252)
179, Forretress (252)
176, Magneton (0)
176, Cloyster (0)
176, Skarmory (0)
176, Ludicolo (0)
176, Breloom (0)
176, Metagross (0)
174, Slowbro (252+)
174, Snorlax (252+)
174, Steelix (252+)
166, Vaporeon (0)
166, Umbreon (0)
166, Scizor (0)
163, Dusclops (252+)
159, Slowbro (252)
159, Snorlax (252)
159, Steelix (252)
158, Tyranitar (0)
156, Weezing (0)
156, Lapras (0)
156, Porygon2 (0)
156, Swampert (0)
149, Dusclops (252)
146, Machamp (0)
146, Exeggutor (0)
146, Ursaring (0)
146, Blissey (0)
136, Chansey (0)
136, Donphan (0)
136, Hariyama (0)
136, Regirock (0)
136, Regice (0)
136, Registeel (0)
126, Marowak (0)
126, Armaldo (0)
116, Rhydon (0)
116, Forretress (0)
96, Slowbro (0)
96, Snorlax (0)
96, Steelix (0)
86, Dusclops (0)