No secret here: Low level NL Holdem.
I'm pretty much done with low limit and don't have the BR to play higher limit game.
I do enjoy the occasional tourney (been playing nothing but low level SnGs on line lately), but much prefer a live NL cash game.
Omaha (or a delaer's choice game) are fun occasional diversions, but my primary focus is a NL Holdem Cash game.