Depends on the supplement, i find jack3d for that kick up the backside if things are lagging, but normally i take no shotgun/sp250 as they aren't stimmed to the eyeballs.
L-glutamine is questionable, as already said a good whey blend kind of negates the need.
Mp have just started selling d-aspartic acid, which for me is a great natty test booster, it's a simple amino acid but for me does a very good job.
Today on the quads machine i was maxing it out at 115kg and still felt i could have gone futher, so for me that is a better product to go for. Naturally some respond better than others.
Cod liver is a given and is staple, coq10 is debatable at best.
The most important supplement is food, and lots and lots of it, along with quality training and sleep, half of these supplements are questionable at best.
Glucosamine/msn is good for the joints, even better when used along with cissus, i used to get a twinge in my lower back, never injured it just something about squats would set it off, but thanks to cissus it's much reduced so as you can imagine i love the stuff.