Creatine, ZMA, Vitamin D, melatonin, BCAAs, pre workouts, I just dropped Ashwghanda. Also not really weightlifting supplements but I take St Johns Wort for mood enhancement / depression (have been since pre-TRT days) and started low dose (5mg) cialis daily a few months ago for BPH (don't think it's helped much).
I think it depends on your diet and workout routine. If you have a good diet and a solid workout routine which is actually damaging muscle fibers then supplements may help.
Pre-work out (I like Pre-Kaged)
L-Arginine 1 gram
Quality Whey protein with BCAAs
Fresh Spinach in my post work out shake
Multivitamin (Orange Triad, Vitaform, Now Adam)
If your diet is crap or your work out routine is half ass then all the above is a waste of $$ except the multivitamin.