rofl @ windansea being mellow... SD has so many options, but i'll just agree with everyone and suggest you go to blacks. there will be a crowd in the lineup but it's spread out with plenty of waves. watch out for those canyon sets =) if it's classic and the crowd is maddening, try scripps pier just south of there.
if you're looking for more uncrowded options, your best bet are the beachbreaks throughout pacific beach and mission beach. if it's too big, try the north county beachbreaks in carlsbad or oceanside. if it's really really big, check out coronado if you have the time or hit swami's in encinitas which can handle just about any size.
i typically use slater's armor configuration for southern california - 3/2 with 3 mil boots, sometimes 1.5 mil gloves if it's around dawn. 4 mil will work too if you're used to the added weight and restriction. o and stay away from storm drains and rivermouths if it has rained recently...
also, to act like a local, just make sure you stare a lot, if you know how to give the stinkeye that's even better. have fun!