i used some local brands in order to save some money but they always gave grainy images and were not up to the quality. so its better to go in for a branded webcam as they offer excellent quality and more importantly-warranty! logitech is the first name i can think of while trying to find a good webcam. they make good computer products and its no exception in this category as well. the pricing is also well-balanced i think - not too high and not too low either!
you pay for what you get... it always pays to try and get one of the well known brands because they always tend to have better quality stuff... like logitech mentioned above