I'm going to have to say the 360. It fits so much better. It just feels right. While I only have experience with the Sixaxis, the shape is the same. I think biggest problem I had with that is the weight. But the DS3 fixes that, but I still say the 360 controller.
When you look at facts like cheaper games, more good games, mods (yes mods are great and add so much MORE value to games), customization and greater online communites, PC gaming generally comes out on top. But to say that PC gaming is for everyone would be completely wrong. You have to like it. If you like consoles, fine, but stop trying to convert us. And vice versa, stop trying to convert console fanboys, I don't want to play with them.
If anything, they should sell games at slightly reduced price because they aren't selling any physical product. So no spending money on dvd, manual, etc. And if you want, you can request the disk and manual for like $5 or something