This whole argument that crops up over PC vs Console is stale and silly. Nothing is stopping anyone from owning both. If you have little enough money that you need to worry about it, then you probably shouldn’t have either, in most cases.
But let’s talk about why you would want to buy a 360.
First, you have live. Live has tons of features, including streaming netflix, automatic patches for games, generally good matchmaking, built in voice chat for everything. Having a friends list is nice, you always have people to play most games with. Achievements sound silly too, but they are a cool thing, a little bit of bragging rights and some extra gameplay objectives, and a sense of completion.
The console itself is easy to set up, has a lot of available games, and looks very good on your hi-def TV.
One big draw is that you can get gamefly or go to blockbuster and rent games. I’ve played a lot of games that I would not buy, and gotten enjoyment out of them. There’s no install procedure or any messing about. There are also a lot more used titles available, so you can build a permanent library pretty easily.
Secondly, if you think FPS on a console is worse than on a PC with a mouse, you might or might not be right. But every other player is using a controller too, and you can easily get good enough that you aren’t going to be thinking how much better this would be with a mouse.
I’ve never had a problem with MS tech support; when my console died, I had another one within a week. They also threw in a free month of XBL.
So here’s my take: I’ve had a 360 since Gears of War, and I use it every day, either for gaming or for netflix. It can be fun when I have friends over – PCs generally not so much. I don’t have to mess with it or get drivers or worry about viruses or anything else. It’s a pretty inexpensive purchase that has more than paid for itself. You really won’t go wrong buying a 360, or even one of the other consoles, although I feel that the 360 has the best combination of good games, online functionality, price, and graphics.
Frankly, the only hurdle I see in the OP is platform/genre snobbery.