Fish oil is useful in extreme amounts. I didn't find a useful dose until I took 6 capsules at a time. It helped me with knee joint pain.
C4/Jack3d/whatever is 99% caffeine. They taste bad, they're expensive, and I have such a high threshold for stimulant effect that the price/dose is retarded. Caffeine pills are really, really cheap.
I take Animal Paks as something of a super multivitamin, never looked into the other Animal products, so I'll have to get back to you on those. Currently, I've never heard anyone worth listening to push any of their products except Animal Pak. Actually, I've never even heard of insignificant people pushing their other products. Gimme a couple days to research. My guess is that they won't be worthwhile, would be nice to be proven wrong, though.
Edit: Almost forgot about the beta alanine. That stuff is decent, but buy it separate... no need to use jack3d. It's cheap, too. I found a slight benefit to it, but not enough to like getting that 20 minute prickly skin flush (harmless, but uncomfortable) from it.