Veganz is a good place to start but avoid the posh restaurant they've put in upstairs, the cafe and supermarket on the ground floor has a selection of bagels, wraps and snacks and a whole lot of cake (avocado blueberry and lime cheesecake mmmmm...), smoothies and fancy coffee stuff
tanneb.de/ does vegan waffles (amazing!), around the corner(ish) there's a place called Rootz which also does cake and other cafe stuff.
Voner does excellent seitan doner/kebab type stuff, they had like a garlic tahini sauce, get that on everything...
Delores had some nice veggie/vegan burrito options, apparently it's "like Chipotle but European and better", either way you get a lot of guac and the burritos were the size of my head. Yellow Sunshine does junk food stuff (wheat burgers and things) if you're into that, I wasn't blown away but figured I should probably try a vegan currywurst and then sat in the park opposite drinking beers all afternoon. There was a great Sudanese takeaway nearby too but I can't remember what it was called. Huge portions of idon'tknowwhatbutitwasnice and a load of the Sudanese version of falafel was thrown in by the owner just for having a chat with him it seemed!
Dada falafel was great for falafel, their website isn't that helpful though!
There were a bunch of other good places, I'll ask Lucy this evening as she'll remember what they were called while I can only remember what I ate!