When we were mere tourists to San Diego, we really loved Balboa Park, as it seemingly teemed with life at the museums, Prado Restaurant, zoo, etc. The architecture is very charming (a remnant from a World's Fair-type exhibition in the early 1900s), and the space itself is enormous.
We later moved to the east side of the park. I have to say that side of the park is not exactly exciting. Sure there's a public golf course, but if you don't play there's not that much going on for you. The east side also has a dog park, and some paths through the canyon. Unfortunately, we were scared off of canyon walks after hearing about the black widow and other poisonous spiders, not to mention snakes and scorpions. Eww!
The portion with the museums is surprisingly unpopulated on most days of the year. Sure it does get people there on sunny, warm weekends, but not like you think it would. The museums alterate "free day" on Tuesday's which is nice. Lots of picnic areas, although it can be kind of chilly here most of the time -- I'm assuming that's because it's at the top of the hill. The cactus and rose garden are often missed by tourists and locals alike, and they are a great place to read or picnic as well.
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