I prefer gaming on my PC too "now" I really never got into gaming on a PC until recently but as soon as I did I honestly haven't turned on any of my consoles unless I am playing a multiplayer game with friends over or the occasional tiger woods 09 on the Wii.
I feel that the keyboard and mouse control (once you get used to it) is FAR superior to that of a controller. But if you like the controler feel you can use a xbox 360 controller as well as other controllers for the PC as well. If you have a wired xbox 360 controller that came with I believe every xbox 360 it has a USB connector on it and can be plugged right into a PC and for me Windows got the driver for it and it worked perfect. I use a controller for Devil May Cry 4 but use a Keyboard for all my FPS (first person shooter) games.
The graphics are better in my opinion and online play is free. Although it is also free on PS3 AFAIK
but I don't have one of those. On xbox you have to pay to get the same online service. Another thing too is the sites like STEAM, and XFIRE where you can buy and download games/demos, save a friends list, and join groups and clans and stuff.
I like having the option of getting a sale on a game without having to go to the store and look at all the games to see if there is any on sale (which never seems to happen with console games anyways)
Plus when I want to switch games I don't have to get off my lazy but go to the console take the disc out, put it in the case, take out the other game, check to see if its dusty, scratched, fingerprinted, or what not then put it in and go back to my seat. On a PC I can just click exit and then click the shortcut for the next one i want to play...
All in all I prefer the PC over the console but I still have consoles for somethings such as Madden, Tiger woods golf, zelda, mario kart, and other games you just can't play on a PC. But if there is an option of playing on the pc thats what i get