so far i have used

sns creatine e2 matrix
bsn cellmass
and dymatize xpand

i got the best strength gains on the e2 matrix and best pumps on xpand. cell mass didnt do much for me in either category. right now i am taking xpand with NO infuse by legal gear. NO infuse is awesome, if you are looking for killer pumps check this stuff out. i think my top choice would be the e2 matrix stacked with some other NO product so i could get the best of both worlds.