HAHA, I know how you feel. There just seems to be an infinite number of scales! Don't worry though, the more you become familiar with them the better you'll be at the end. A good guitarist can be measured depending on how well they improvise, not how well they copy. And scales allows you to do just that, they allow you to recognize patterns in the different notes and build up on them. Since practicing scales can bring little or no fun, unless you are really into music theory, what I do is warm up everytime I'm going to play with the scales. Run about ten to fifteen scales everytime you start and you'll be proficient enough to play whatever you like afterwards... It's the only way you will be able to build those amazing solos you hear from bands like Led Zeppelin all the way to Ozzy (at least when Randy Rhoads was with him).