There's only certain Biotest supplements that I really can't go without... as if I feel 'off' when I'm not taking them. Those are:
Flameout - I take 6-7 of these a day. You can just do regular fish oil, but I like Flameout because it has more DHA than EPA. I get much leaner from upping the dosage to this, even up to 8 Flameouts a day.
SWF/Anaconda/MAG-10... Mix this with 1L, and the way my muscles feel during a good session is indescribable. They just feel 'pumped' and hydrated as hell. If there was every a feeling for 'anabolism', this is it. BUT, you don't need to spend this much money. Focus on: electrolytes, lots of water (at least 1L!!!), BCAA, creatine, beta alanine. Beta alanine is one of the best supps in the world. Biotest just makes it damn convenient with the liquid flavoring and Nalgene bottle.
Power Drive (or brain neurotransmitters in general, there is a LOT of science behind these) - simply put, when I don't take it, something is 'missing' in my workouts. However, I've started taking 2 pills of Fast Brain 2.0 by Poliquin, which I have to say, is my all time favorite supplement. The focus I get is out of this world.
It has 100mg of phosphatidylserine, a great neurotransmitter (which is in Power Drive as well, in the same amount), as well as huperzine A (it's main ingredient), bacopa, vinpocetine, and ginkgo. What I did today is: 1 shot Alpha-GPC/2 Java Stim (caffeine)/2 Fast Brain pre-workout, and Power Drive post-workout. Shit is amazing, best drive in the gym I've ever had.
Receptormax - my workouts are always better when I take it. It might be placebo, but I doubt it, I have been taking it for awhile. I attribute it to the ALCAR and R-ALA.
The rest of the Biotest stuff, I don't really notice or could do without (but I don't, hehe).