For Halo 3 which maps do i need to play most matchmaking games?

[sexy]

In matchmaking, the only thing i can play is team slayer. I know you have to buy maps to play everything else. Which ones do I need? I don't want to spend to much money on the packs.

 

[Jasper Cat]

All DLC really... Without any DLC (except the Free Ones) you only get two matchmaking choices