I've tried a lot...lol (hence the old adrenal fatigue

)
My opinion is kind of skewed, too, because once my adrenals were shot, I was still using stuff and had to dose higher because I didn't have ample time off.
N2KTS is at the top of the pack. I thought it looked identical to Jack3d when I first saw it, so I wasn't interested, but when I became a rep, I wanted to try all of the products we offered. So, I did, and I felt more from it than Jack3d, liked it more, and loved the taste (grape koolaid? yes please).
I always used to love Jack3d prior to that, but my sensitivity built up very quickly (working out 5-6 days a week is a downfall when it comes to this because you use a pre-workout SO much).
Wyked was good. I was using it at about 1.5 scoops and I felt some good focus from it, but wasn't over-stimmed (that was in April/May and I was unable to feel stimmed-out any more).
NO Xplode (original) didn't give me a stim feeling at all; decent focus though (one of the first products I used a few years ago).
NaNO Vapor was probably the craziest I've ever felt on a pre-workout stim. I took that back in college and would want to puke it was so intense. I absolutely loathed the flavor.
Out of all that I've tried (a lot), those 4 are probably the most stimmed feeling I've had as far as a pre-workout specific product is concerned. The NaNO Vapor probably hit the hardest, but it was one of the first products I ever used in this category.
Hands down the most intense stim feeling I've had has been from 200mg of caffeine and 25mg of ephedrine, though. Especially at 3x/day spread out by 4 hours, it was intense.