I play all games using keyboard and mouse.
I don't really like console games so I generally do not touch controllers. I like keyboard and mouse because they offer better accuracy and binding keys for games with a lot of different command is more suitable for a keyboard than a controller... at least in my opinion.
I think the last time I touched a controller was when Halo 2 came out for Xbox. A friend of mine loved inviting people over to his place. At which point he would break out his two Xbox if enough people were interested in playing games.