Animal Pump is more like a pill version of the Storm/Shock Therapy stack so I will say either Animal Pump or the Storm/Shock Therapy. Animal Pump already has creatine, stacking it with Storm will be overkill, IMHO. The grape flavor of Storm and Shock Therapy is preferred. BTW, the red pill in Animal Pump is the energy complex. If you work out at night or simply do not want that much stimulants, you can leave it out.
Animal Pak is a very popular multivitamin. Some people use NOW Adam. I bought it but haven't tried it yet. I took GNC Mega Men before and I am currently using Nature's Way Alive.
BCAA2000 is a BCAA only supplement while Animal Nitro is an EAA which includes BCAA. Which one to take depends on your goal, I think. Some say BCAA for cutting and EAA for bulking. I personally like Animal Nitro. For BCAA, I use Excell by Anabolic Innovations.
I have used tribulus and ZMA before but I did not notice much difference. However ZMA really helped me sleep with vivid dreams. You may give them a try.
Real Gains is a good weight gainer and I am using the chocolate now. Another good one is Cytogainer.
Just my 2 cents.