L-Glutamine - Apparently if you are going to use only one supplement, this is THE supplement to use. It's relatively cheap as well.
Soy Protein Isolate Powder - sometimes use this, causes bloating though
Creatine - Have tried a few brands over the last few years, but it always cramps me legs and hurts my lower back when running, so I don't use at all now.
Vitamins and minerals - Multi-Vit, Multi-B, B12, Iron, Magensium, Zinc, Selenium, Garlic, Ginseng, Chromium, co Q12 - I don't always take all these, I usually purchase them when they are on special offer.
I don't neccessarily think that you have to supplement as a vegan or vegan athlete. Sometimes I do not supplement at all and my physique or fitness doesn't suffer at all. I just take supplements as an insurance policy. Apparently vitamins and minerals can be a waste of money as some brands just pass straight through you without actually being absorbed - they're just full of chalk and binders etc. Obviously I prefer to get my needs from my diet, and that is why I eat a lot of wholefoods, fruit, dried fruit, vegetables and seeds.
Once you get into the habit of visiting health food stores and buying a few supplements, you get exposed to different products you previously weren't aware of, and you tend to buy more.