Always online from one of these:

I like buying stuff I can actually see, feel (and taste) before I pay for them, but apart that tasting is seldom allowed carrying 20 pound of whey on my bike isn't easy and prices are significant less when I buy then online. Even importing from the USA is often cheaper than buying online in the Netherlands some of the times.

Also buying online gives me a huge choice, whereas when I go to the shop I am bound to the productline that shop has.

So I buy my protein and creatine online, but my straps and elastic bands (back when I was afraid to skip a workout) I bought in the shop (just as some supplements as lineseedoil, dextrose, cinnamon, vitamin-C, and all of my food)
I used to but my products at www.netririon.com

Now there is a supplement store located here locally that sells products for the same cost..

www.ytfs.com (Your total fitness shop)

This is where I buy my protein and creatine supplementation. Now for vitamin supplementation I buy products from www.reliv.com . The classic product is in a powder form so it's absorbed into the body easier than taking a pill. For my Omega's though I buy from a Natural Health Food store (Barleann'a Flax Seed Oil) and two products from Natural Factors called Salmon Oil and MSM Joint Formula.
I get mine from a friend who imports supplements. he has no online or physical shop. just his house.
and i bet he orders by bulk from an online store. very much cheaper than buying from a physical shops. they price too much. :confused:
I used to work at a string of family owned GNC's in San Antonio. They still give me my employee discount. They also carry unique products that corporate GNC's don't. They're always looking for ways/products to distinguish themselves from other nutrition stores.
I always buy at physical shops. I'm not exactly "from around here". I'm from far far away :D

I used to buy at GNC. Their chocolate whey protein supplement tastes great! Unfortunately, the last batch I bought had some problems with it. And I figured it had too much cholesterol anyway (can you believe it, 70mg of cholesterol per serving! )

Anyhoo, so I switched to a local sports store, Chris' Sports. I buy Optimum Nutrition's Whey from them. Similar taste to GNC's, far less cholesterol (only 10mg per serving), and 3g more protein. If it's out of stock, I just buy Designer Whey.

Not really much into supplements though. I drink a serving of supplements only right before a workout.

Regards! :)

With all due respect it would be impractical for me to buy here in South Africa from the US.

There are various online choices here, but I usually buy at a naturist shop, it is the cheapest.

At the moment I use, extreme grow of muscle science and creatine monohydrate of supplementssa.
I filled in the poll but I'm not really a good candidate. The only supplements I bother with are whey (which is super-cheap at Costco), omega-3s (fish oil, cheap at Costco), a daily multivitamin (cheap at Costco), and creatine. If Costco had cheap creatine I'd probably buy it there. :)

(I also buy a lot of chicken at, well, guess. :D )
Silaren, I recognize you from the gymrats community on LiveJournal!

Funny to see your post now, because I work next door to a CostCo. Just got back from there--bought about five pounds of lean ground beef and a tub of cottage cheese. I get my whey there, too--can't beat six pounds for twenty bucks.
I buy from bodybuilding.com. The biggest reason I stick with them is the no hassle shipping to my PO/FPO AP boxes. A lot of places I have tried to shop do not ship to FPO/APO/PO's, or they charge unreasonable rates to do so. There are a lot of deployed military guys out there that buy supplements, so whatever you do, make sure that you provide them with service too, or you'll be missing out!
Good to see some Aussies posting. I live in Melbourne and the physical store Evelyn Faye in the city is usually the cheapest for protein and creatine. They also have a website: www.completehealth.com.au. As for glucose powder, the cheapest I know happens to be in the 'homebrew' (beer) section of my local Coles supermarket. $3(AUD) / kg - and I go there for my normal food shopping all the time anyway! So alcohol has (indicrectly) helped with my hypertrophy afterall ;)
I agree with Edziu. I buy at a local Supplement Store (that's actually it's name!) - because the two owners are BB'ers and will honestly discuss products with you, make recommendations (not always the most expensive) and just like to chat a while about bodybuilding. I guess I go there for the "ambience". It's not your local GNC, that's for sure!