While the mass market of supplements is no doubt beyond confusing, a person has the responsibility to research what they may or may not be supplementing with.
It's so easy to fall to flashy advertising and slick "pseudo-research" that a guy could be dishing out hundreds of dollars per month---all for expensive urine.
IMO, one should attempt to eat the cleanest, most nutritious diet possible, 24/7. And frankly, that's just damn hard. So, supplementation fits in.
I've been dabbling in nutrition and supplents since I was a teenager, and I racked up a bit of knowledge based on research and trial-and-error. If I'm thinking about taking something new, I ask myself this two questions:
Is there any 3rd party research that's solid?
If not, chances are I won't spend my money. Sometimes, I will try something new to see if it does indeed have a desired effect on my body.
What I'm taking now:
Multi vit/min : Of course---fits in with the nutrition
Concentrated EPA/DHA fish oil: overwhelming postive research makes it a must-have, IMO
Vit C : I've always supplemented this at 1000mg a day, but recently upped to 9,000 mg a day.
Green Tea Extract (ECGC): Some incredible research on it's anti-oxidant properties. Started this in Jan to see if it actually have any thermogenic effects. None I've noticed, that's for sure!---but on an interesting side note, I fall asleep a lot faster. Weird.
ColdFX: Canadian-made supplement backed by a shwackload of research. Been taking it for over two years now, and I haven't had a cold or the flu in two years. Yes, it works.
Panax Ginseng: I cycle this, and it give a noticable boost in enery levels for me. There's some sports reserahc out there backing it with improvement in performance of trained athletes.
And that's it. Of course, there's creatine and whey protien, but those are beyond supplements