Having never owned a console (other than the Dreamcast that's still in the cupboard, that I never took out of the box), and coming from a C64 to Amiga to PC gaming background, I suppose I'd be called a PC enthusiast. Not that I've got anything particular against consoles, I've just never been able to justify owning more than one system at a time. I might get the missus a Wii for Christmas though...
Now, I'd like to believe that the PC has a future as a gaming machine, but as consoles gain more and more features that were previously the preserve of the PC (e.g. online play, increased media compatibility etc) at a lower price than most reasonable gaming rigs, I'm not so sure. Of course, there are those who argue that you don't have to spend a small fortune on a PC, and they'd be right, but you buy a PC (for fairness, let's say minus a monitor) for the price of a PS3, and gaming power-wise I think the PC would still lose out. It's not all about pretty graphics, but they certainly help.
At the moment, my PC can still do far more than any of the consoles in functional terms, but for how long? However for those who really care about technology, and that's a lot of people, I think the PC will always be the format at the cutting edge. Couple that with the fact that the PC is more of a way of life for some people, and there will always be a market there.
As for game genres, the few times I played an FPS on console, I hated it. It may have been because it was Halo though

The controls were so much less accurate, and so much slower I found. With the GTA games I use a gamepad for the driving sections, and mouse and keyboard for the on-foot bits. Best of both worlds. I think it would be tricky to use a mouse and keyboard whilst sitting on the sofa, unless you have a tray on your lap or something(?). Anyway, don't you think you get more variety on the PC? As for the convenience of the living room, I think I prefer to disappear upstairs for a bit to get on the PC. Maybe I'm just not a very social gamer, or maybe games wouldn't be so involving if the wife is sitting next to you reading Heat magazine or whatever?
Think I lost my train of thought at the end there ... even thinking about Halo fills me with rage!