creatine mono: oldest and most researched/studied form of creatine, works for most people not for others, causes water some amount of water retention.
all these new fangled CEE's and tri-creatine malates etc supposedly cause no water retention, and supposedly more people "respond" to it, but they are less studied. also generally more expensive to some degree, but the effective doses tend to be smaller.
most of the other crap they put in supplements (save for a few) will have zero noticeable effect whatsoever. in the end, racking your brain over which creatine to choose over another is comparable to deciding which shoe laces to buy. in the end it doesnt make the slightest difference. just buy some creatine mono or creatine cee and eat some carbs.