The mouse allows for more accurate movement in an FPS, at least for me. You have the entire surface of your mousepad, you can move it slowly, quickly. Those crappy little analog pads they put on controllers have about 1 inch diameter's worth of play and I'm always moving too quickly around.
That's fair. Still, that's mostly limited to the FPS. Plenty of action/adventure/platformers where I'd rather have a controller than a keyboard/mouse.
Also, when you play at a computer monitor you're generally sitting right up next to it while a TV is across the room. Most computer monitors have a higher resolution than TVs unless you have a 1080i/p.
From experience, I can attest to a comparison between a 21.5" 1080p display (on my computer), and a 52" 1080p DLP TV. I've hooked my PS3 through both, and I can say that the TV was a better experience, even from about eight feet away. Granted, the "average" TV you can buy new these days will be more comparable to my computer monitor, but that just evens the playing field.
None of that is to say, "your preference is wrong" but that your preference may be a variable that can change in different circumstances, instead of something locked in based on a single configuration.
