Granville Island is a gift Vancouver offers the world. Rent a bike and head over there for the day. When I was there last I was lucky enough to be there for the Honda Celebration of Light at English Bay beach, which I was also lucky enough to experience for the second time. This usually happens around end of July-early August, definitely check it out if you're there at this time! Vancouver is a beautiful city, also if in the budget I would recommend a boat cruise at night fall, stunning sights.
Insider Tip:Avoid East Hastings St. Especially at night. You will understand why I say this even if you visit during the day. Also bring an umbrella, it can start raining at any given moment.