Budget mate?? .For as cheap as possible get those el cheapo tech-com ones as well which can die at any time and no can see your image even you
My advise get a decent one Like the Microsoft Lifecam HD 5000 ,its your best bet for HD cams ,its decent but only annoying issue is that it keeps focusing even if you make little movements.If you want to know all about web cams head to Cowboyfrank Web cam Review.He is the only one who has done extensive reviews on web cams.
Even i had tough time choosing which web cam but after reading his reviews i made up my mind and got a Logitech C905 for Laptop( its expensive ).