I try and hit up Rodney's whenever I am in Van.
Located on trendy Hamilton St. it's got some serious character. Sit at the bar for a great view of the oyster shucking and some lively chat with the bartenders. Staff is friendly with plenty of personality. They have an oyster happy hour 4-6pm (if I remember correctly) where it's half price oysters. And seeing as many of the oysters and ingredients come right out of the ocean around BC the food is beyond fresh.
And in case you were wondering, this place has the best selection of oysters I have seen yet. 11 different kinds on the last visit. My favorites being Fanny Bay and Kushi. Good selection of craft beer on tap too.