I've been working out for almost 15 years now. I've tried all kinds of preworkouts. 95% of the time I just use caffeine.
My favorite--this is more of a treat than anything:
1-2g Kratom (hopefully a strain that energizes you)
1 CDB/THC gummy w/ 2mg THC (I'm very sensitive to THC)
Caffeine (a moderate amount)
The least favorite part of my workout is the warm-up, stretching, and mobility work. But with this stack I absolutely love this part. It puts me in a very yoga-like headspace where I really enjoy the pulling and warming up of the muscles. Also, the mind-muscle connection is unreal. I think this is a really great stack for building new or reinforcing muscle recruitment patterns. I just love being in the gym and exercising when on this stack and that's what it's all about after all.
I take creatine on a daily basis. It just makes me feel good and I feel like it has nootropic effects and there's a lot of literature that demonstrates it's ability to improve recovery.
Every once in a while I'll do a stack with ephedrine (Bronkaid--over the counter). It works really well in the gym. I will complete more working sets and usually achieve more reps. Motivation and focus is through the roof. But I feel like it lasts for the rest of the day and I'm racing around anxious and stressed out. I have a hard time being compassionate and relaxing. So it's not really worth it for me.
Agmatine provides a great pump, but I also get a great pump without it. So I save it for when I feel like I might be getting depressed.
Ashwangandha (KSM-66 from ND) seemed to improve my physique somehow and maybe gave me more energy. It's notable but I don't think I'll continue using it because it's hard to justify the cost/benefits.
Nothing else has really stuck. There are some mushrooms that I don't think I've given a fair shot and I've heard some things about MACA so I'll have to give that a shot as well.
Oh, I should mention LGD-4033. The closest thing I've done to a steroid. Definitely made me stronger and feel better. Too good. I didn't want to come off it. When I did, I felt depressed, which may very well have been due to the suppression of testosterone. If SARMs could bring your testosterone up for a period of time and then bring them back down to baseline, I'd continue taking them. But there is always a period of suppression that, in my opinion, isn't worth it.