For a smallish shop the Incredible Nutshell packs a lot in, and since it changed hands earlier this year the range has improved. Probably the best vegan range in Sheffield including stuff I haven't seen elsewhere. It's a small independent and so not the cheapest and it's out of town, but well worth a visit. Sometimes there are even free samples to be had ;) They currently open 'til 8pm on Wednesday and you can stay up to date on their Facebook page (https://www.facebook.com/TheIncredibleNutshell)
Cons: Not the cheapest, Too far away from my house!