Ok for TA you need a good monk or you're shot. I'm decent not good...i can't deal with good mesmers very well.
For anyone melee a nec makes it easy just put a bunch of anti melee hexes on your bar.
For dervs i recommend weakness or prot spirt b/c they hit so hard. also i tend to try to kill the dervs last because they have good self healing and take a bit to get down.
Sins are easy to counter...interupt on of the skills in their chain..whether it be with clumsiness or savage shot doesnt matter...d shot would be best cause they cant do anything for 15 seconds.
Paragons are useful to have on your team, They provide good damage and can provide support for monk.
Also one other besides monk bringing conditon removal helps in case monk is dazed
My favorite team has been Monk, Nec, Ranger, Sin.
Thats all I have for now...