I also like space sims (like Freelancer) and flight sims (Flighgear, Ace Combat). I guess that would be the simulation genre. A lot of games these days also combine genres together, so a lot of games I like could not fit into a single genre (e.g. Mass Effect). One of the favorite things which I can't play on the PC is Gran Turismo, which is also a racing simulator. So I guess my top 3 genres would be first person shooters(or 3rd person), RPGs and simulation games, but I would not limit myself just to these.