Hemavol by iForce. Why? Because it doesn't have 1,3 dimethyl in it (I notice the side effects of products that have 1,3 in it, and I don't want to think about having to cycle off it), nor does it have any type of creatine. If I supplement with creatine, I'll do it separately. I also don't want my proteins, BCAA's, and my pre-workout to overlap ingredients. Hemavol is not a "do all" type preWorkout like others that throw in everything and the kitchen sink into their product.
For those of you taking these products that have no idea what 1, 3 dimethylamylamine is, do your homework.