sho nuff i do, *sprout*. vancouver is a part of the lower mainland, though...so i'm not sure what you mean by "in vancouver or even better the lower mainland". my favourites:
1) the best, by far, is the buddhist vegetarian restaurant on pender street, in the heart of vancouver's chinatown. all vegan, and totally delicious chinese food. try the "lemon chicken" and "peking-style chow mein"! it's also REALLY affordable!
2) sweet cherubim on commercial drive is a cafe/deli that serves vegetarian food and some lovely cakes, pies and cookies, much of which is vegan. their pakora and salads, and smoothies, all rock.
3) cafe du soleil/cafe deux soleil - both are located at opposite ends of the commercial drive in the vancouver's east side. they serve mostly vegetarian in a deli-style restaurant. they also serve good local beers, have great smoothies, and i love having their tofu scrambler for a late sunday brunch. their fries also rock.
4) bo kong - located on main street in vancouver, with a second location just outside vancouver in richmond, this is another, higher-end vegetarian (but not all vegan) chinese food restaurant. my favourites include the "vegetarian steak with sizzling black bean sauce", "chef's special rice" and the deep fried cashews.
5) WaaZuuBee's cafe - another restaurant located on commercial drive, it is not specifically vegetarian, but they have many, many delicious vegetarian selections. they also serve liquor, and play funky house music. it's a little expensive for my tastes ($12 for an entree; $8 for an appetizer), but still a good option if you're going to be dining with omnivores.
6) The Naam - on west 4th in trendy kitsilano. this place is always packed! it's got a great selection of organic dishes, all vegetarian. a little on the expensive side but the portions are HUGE. don't be surprised if, when you get there, there is a line-up, though.
there are other places i haven't checked out, too. i like www.vegdining.com
as a resource.