I try to play with 9-10 players at the table. It's easier to play when the game is going smoothly with classic game tactics. Naturally, I know how to play heads-up, otherwise how would I take first place.
9 player tables for sure. Gives me more options on the amount of chips or cash I will walk away with. It also allow me to be more selective in the hands that I wanna play. With less players at the table I would probably play more marginal hands.