i recently made an uber team, centered around the purpose of defeating mysterial (pbr stargazer colosseum, masters battle set 8)
and surprise surprise, after he sent my other uber team home crying, he got completely obliterated by the new team :D
the team consists of
palkia
dialga
deoxys-D
latias
arceus-grass
kyogre
so, the strategy is that i lead with palkia and a defensive pokemon (back then i used latias). palkia uses trick room straight away (all pokes have 0 speed IV's+EV's) and latias switches to kyogre (specsed kyogre). kyogre spams water spout while all the others support with hydro pump, surf, thunder, and other moves. This was all custom made and my first semi-pro team without any help from smogon strategies :D. anyway, the trick in this is that mysterial's pokemon are all at highest speed possible (kyogre even is choiced to get 50% speed bonus). using this, and the (by uber standards) calamitous low speed stats of my pokes give me the advantage in speed when trick room is used (by either palkia or arceus).
while palkia+kyogre combo can rip through generally everything (as far as i know) this is a good team, with unexpected results in competetive battling.
but yeah, the main problem with ubers is the lack of players, because many are afraid to battle those uber users who don't know what EV's or IV's are... (to be honest, a year ago i didn't know what it was either... i just kept using my 336 sp atk mewtwo and disconnected when it was defeated via wi-fi by an absol XD)