I bought this controller solely for gaming on my PC, as i don't own an xbox360. And really mainly to play Skyrim, as i didn't like how it controlled on the PC. The interface felt like it was made for console too much.
I am actually surprised how many games actually work with it out of the box! Titles like Skyrim, GTA 4, Overlord, Borderlands and Saints Row 3 work right away and some even display the proper buttons on the interface as soon as you use the controller. Also a lot of the indie games from steam work with the controller (for example Trine 2 and LIMBO).
If a game doesn't support it, there are plenty of tools available to bind the buttons and analog sticks to keyboard presses and/or mouse movement. This opens a whole world of customization. I've tried this with World of Warcraft and a game called VVVVVV and it worked great.
It has a descent long wire which i guess is mainly for the xbox's purpose. There is optional software that you can install to make it respond to pressing the Live button, but i don't see any use for it if you only plan to use 1 controller, so i suggest not installing it. Windows 7 (and probably Vista too) will pick up this controller right away so you don't need to install things from a cd-rom.
So in short, if you're into gaming but still prefer a PC over a console like me, this is your thing! I can safely say that pretty much every new game that comes out that is also on the consoles will work with this controller out of the box. I should have bought one of these ages ago!