Family and I (college age kids) are heading to San Francisco for 2 1/2 days in March for part of our Spring Break. Looking for must not miss restaurants. Not really looking for fancy, high end. We get that in Dallas. Just great local food. Eats we definitely want are dungeness crab/fresh local seafood and dim sum in Chinatown. Staying in Union Square so looking for good breakfast joints too. Never been to San Francisco so any help would be greatly appreciated.