Slapstick comedies? Power fantasies? Mysterious conspiracies? Scooby Doo adventures? Heck, basic dungeon crawls? At the moment I'm feeling either gritty mystery or superheroism.
That said, I've been gaming long enough to realize that there isn't any one "right" way to play RPGs. The key is to find a group who agrees upon a style. Most of the time when I encounter bad games or bad players it is because of a conflict in expectations. Likewise, most of the good games and good players are a result of either people willing and able to adapt to differing expectations or a rare gm who is able to properly define their game from the outset.
What is my default style? I enjoy some crunch to the game and system, but I like to do my number crunching between games. I tend to be vocal, voicing opinions and interacting with the world. I like to keep the conversations and side talk in character. It irks me when actual role play is interrupted for unrelated out of character diversions.
My characters tend to have at least a couple of layers and it is generally my hope that we'll get beyond the surface. Heroes with a dark side and monsters looking to do right by the world are right up my alley.
I do tend to push the rules pretty hard when it comes to character creation. That does come with a bit of power gaming, but I'm most happy when I can min-max towards something flavorful and fun rather than game breaking. However, I accept it well when a gm rejects something on my character sheet.
This comes hand in hand with respect for the rules. I like it when games actually stick to a set of rules. House rules are fine and so is hand waving. Whatever rules we go by, I'm going to learn them and will hope that others make at least some effort to do the same.