I'm a big fan of the Art House for tea and cake - all of which is vegan. It's great to be able to not only have vegan cake but to be able to choose which one you fancy!
I've also had some nice light meals there.
It's not a fancy place - it's a community interest company. Almost all the staff are volunteers and service can be a bit slow but never so much that it's a problem. I always find it really friendly and such a breath of fresh air compared to the high street chains.
Cons: service can be slow, noisy if there's live music