Tons of beaches to go to (La Jolla, Coronado were my faves. Tons of surfing there)
Sea World was ok
Zoo was pretty cool (there's two of them)
Balboa Park (The zoo is located there along with a million different musuems. Balboa Park | A landscape of Arts and Culture
Old Town is neat too (Old Town San Diego Guide
Downtown theres a few nice roof top lounges. (Called Gaslamp District http://www.gaslamp.org/
I don't really see many clubs there, more like restaurant/bar turn into clubs at night. There's happy hour almost everywhere from 3-6pm. American and Mexican food is huge there. Asian foods is pretty limited, and most of it kinda sucks compared to Vancouver. I'd say check out urbanspoon.com for suggestions. Haven't tried anything there that really wowed me aside from Hash House A Go Go. HUGE portions I warn you.
I'm down there alot more than I'd like. So I know quite a bit about it.
LA is about 1.5 hours away. More to do there usually. If you go to beverly hills area, try "The Stinking Rose". Awesome food. http://www.thestinkingrose.com/
. LA has alot more night life and more to do I think. K-town was fun. LA there's the usual Hollywood, Beverly Hills, Outlet Malls, Six Flags, Universal Studios, etc etc. I haven't like gone clubbing there, but I heard it good but can't think of the names right now.