Harrods at Martin Place stocks Creed. You can go in there and have a sniff. But unlike the departmental stores, they are held behind the counter.
So the clerk will spray onto a piece of paper then hand it to you - I personally find it crap because I would feel bad asking for a sample of all of the Creeds and not wanting to buy any - I buy online!
DJ's in the city will stock some niche brands where you can sniff to your hearts content, such as Amouage, but I've asked before about samples and they usually don't have any. the only exception is the Tom Ford counter, where if you're nice enough, they will happily decant you a 4mL sample of any of the private line.
I have TV, oud wood, violet and some other i can't remember right now just by being presentable and nice
I personally can't think of many places that actually give you samples to sniff, most just have the tester in store.
If you're interested in trying niche brands, i would suggest hitting up luckyscent and just ordering samples. I've many a bag from there since the past year and they have been quite excellent.