I have granite counter tops and I love them!  What I don't love is the streaks that I could never seem to completely get rid of.  I felt like I was spending all of my time cleaning granite counter tops and they never, ever seemed to get completely clean. It got so bad that I didn't want to let any of my kids come in the kitchen for fear they would spill something or touch the counter tops and then I'd by stuck trying to get them streak-free again. 

After about six months of trying every method known to man to keep these silly counters clean, I finally found something that works, and the best news is that it's completely and totally free.  Well, with the exception of the purchase of a few microfiber cloths.  

So here's the secret to cleaning granite counter tops with out the streaks that seem to get left behind no matter what you do.  Take one microfiber cloth and get it wet.  Wipe down the countertops.  You only need to use water for this step.  Once you have completely wiped down all of your counters, take a dry microfiber cloth and wipe them completely dry.  The only trick to this method is that you absoulutely must wipe the counters dry when they are still wet.  I don't know what is in the microfiber that gets rid of the streaks, but my granite counter tops look cleaner than they have ever been in the past. I don't spend the money on commercial cleaners and paper towels and I have counters that look like they belong in a magzine!  Hope it works as well for you!