It all depends on the quality you need for skype. Logitech ones are quite good, you dont need to go for the whole 1080p ones if you're not in a demand for a solid crisp clear webcam session. Microsoft lifecam have gotten some great reviews. So when you buy a webcam think of what you are gonna use it for. Maybe you wanna stream in the future, then it might be nice to pick up an 1080p one.
I didn't think to ask, but how's the audio with the built-in mics?
The one i linked is actually more clear than any mic i've ever used. It does pick up all the background noise unfortunately, but it's very clear. I'm fairly sure there'll be a voice clip test of it on Youtube or such.