I have tried a few of the generic forms of creatine and never like them much.  I always got an upset stomach, held on too more water than I wanted too and never saw much gain (some but not much to put up with the sides)  Well, I tried a friends creatine one time when I was out and LOVED IT.  It is called Creatine Glycerol Phosphate by metabolic nutrition.  It is not very expensive, I get no upset stomach, little or no water retention and have noticed some serious assistance in the gym from it.  I won't say never, but I don't see myself using any other creatine anytime soon.  It works very well for me and I would reccomend it to anyone.