You do get a different class of games for PCs compared to consoles - e.g. SimCity 4wouldn't work so well on a console platform. But if you have the correct hardware on the PC then you can pretty much run any game.
Graphics hardware wise, PC graphics are continually improving. This was PC graphics a couple of years ago before Playstation 3 was out:
I'd say that PC graphics cards coming out around now and with DirectX11 in Windows 7 and Vista, consoles will probably have that level of graphics later on. But PCs can have it today.
While you have fixed hardware in a console, and that makes it idiot-proof for sticking in a games disc and having it run and for games developers, that also means that it will be outdated from the moment it goes on sale. E.g. if you have a PS3 with a 40GB drive, wouldn't you be envious of the people who are buying current ones that look smaller and have 250GB drives in them? You'd have to replace the entire console to upgrade to a new feature set. But on a PC if you want a bigger drive, you just get a bigger drive.
Well, it all depends on what you want really. There was an interesting article I read comparing Telltale games on console and PC and there were definitely advantages on the PC versions (besides the free DVD and episodic releases) - things like the saved games being able to communicate with each other (DeSoto decals being carried forward to next episodes in Sam & Max season 2 for example).
I'd guess most people with consoles must also own PCs anyway - they do much more than just games - you can shop online, buy stuff, visit forums, watch movies, download music, burn photos, email, video...
When it came to deciding should I get a mid-quality PC and a PS3 and an XBox, or should I just get a PC that does it all, I'd go with the PC that does it all and can be upgraded when I want to do more. The only problem is console exclusive games. Which would be solved if they just released everything on PC too.
On that note, I don't mind games being developed for XBox because most of the time they also get released on PC as well. I was thinking that's because Microsoft made the XBox hardware similar to a Windows PC, so it must be easier to develop simultaneously on both.