I've tried a few, namely: Bullnox, NO Xplode, Neurocore, Assault, Jack 3D, Super Pump and a few others. The one that worked for me was Assault. The one that didn't was Bullnox.
But what may work for me won't neccessarily work for the next guy and vice versa. So I think you need to find what pre-workout suits you and what you are trying to achieve. So it's a bit subjective IMO.
I'll give Razor 8 a try, I'm always keen to try new supplements