I chose #2, although I like all three choices when they're done properly. However, I love 'fluid' gameplay where you can just string attacks together and that tends to occur most in #2. Not to mention, a fair amount of games in #2 are 2D pixel-based, which I prefer over 3D for my action games since they have 'pixel-perfect' precision where you can really get a feel for the exact range of everything after a while (that and you don't need to usually worry about camera issues).

That being said, I still do really like the other two categories. 3D action games can often be just as fluid as 2D ones and they tend to have higher possibilities for environmental puzzles and in generally make you make use of the environment and its shape more often while fighting. More traditional MMORPG's I actually may like even more than 2D action ones when they focus on party-play and the classes supporting each other to accomplish tasks...but that pretty much either never happens or is all crammed into endgame and even then most traditional-style games simply don't crank up the difficulty enough.