Currently having a lot of success at the battle subway using:
Weavile - Jolly with life orb
Fake out
Night Slash
Ice Punch
Brick Break
Gengar - Timid with Focus Sash
Shadow Ball
Thunderbolt
Focus Blast
Destiny Bond
Garchomp - Jolly with Choice Band
Outrage
Fire Fang
Earthquake
Stone Edge
My tactic is pretty much to hurt the enemy as much as possible before they get a chance to hit me back, since my team is quite frail. This helps to avoid hax in the tower.
Weavile is the ultimate dragon slayer :P, can switch to Gengar to cover it's fighting and Bug weaknesses, and Weavile can switch to Garchomp to cover it's fire weakness or against Jolteon who is one of few pokemon who is able to outspeed him, whilst he covers against dragons, ghost and psychic types that could otherwise hurt the rest of my team.
Gengar is an excellent wall breaker with focus blast and can hit everything for neutral damage with the combination of shadow ball and focus blast. Also, it can practically gaurantee at least one KO if my team runs into trouble with destiny bond, whilst Garchomp just rips through anything that is left with choice banded outrage :P
Seems to work pretty well in random matchup too :)
The others I have are Ambipom, Galvantula, Azumarill, Heatran and Volcarona.
Galvantula and Azumarill make a great doubles team- covering each others weaknesses, Azumarill hits first with water gem powered up aqua jet, with huge power is pretty baddass, and Galvantula with a 91% accurate Thunder, then Heatran which can switch in on so many threats and wall them all day, whilst doing a lot of damage.
Also love Ambipom- technician boosted, normal gem fake out, followed by return ftw :P