Mult-Vitamins- I do notice a difference when I forget to take one, more sluggish through the day
Fish oil- I've read up on studies(too bored to read the whole damn thing, just skip to the abstract and figure out if it worked) on cancer patients taking fish oil with protein increasing the effect of the protein. I feel like since I've made it a point to take fish oil with some kind of protein that lacks fish fat, that it helps.
Protein Powder- I'm probably one of the few that see's more progress with quantity over your ultra-micro-coldbrewed-instantanianized-myotrophically filtered horseshit whey....just get a bunch of protein, use the powder to boost the amount of protein you take.
Creatine- Of course!
glycerol- yup
supps pertaining to insulin sensitivity(chromium polynicotinate, R-ALA, fenugreek, metformin) they help
I actually do splurge for a preworkout like Xpand about once a year when I tend to run out of samples to play with. I do feel using it sparingly like that helps increase some focus in the gym, but it's not a crutch.
basically everything else is crap