It totally depends on your budget and preferences, but local specialties are seafood, Chinese, Pacific Northwest, everything
Raincity Grill is great for local '100 Mile Diet' stuff though, if you really want to check it out. Pricey though, but you get what you pay for - in a good way.
I like Rodney's Oyster House as a funky way to introduce my out-of-town friends to Vancity. Also recommended is anything along the Robson strip (ie: CinCin, Tropika) or the Denman/Davie West End area (incl. Kintaro). If you do hit up Kintaro, try their cheese ramen. Yes, I know it sounds crazy, but man up and try it - you won't regret it.