First of all, congratulations on coming to visit my hometown of San Diego California. Before you post the inevitable, "where should I eat" post, here are few things to keep in mind:
1) San Diego County is HUUGE. Now, not huge as far as population goes, but as a general area, we're talking 4200 square miles with over seventy miles of coastline. It can take over an hour to drive from San Ysidro (southernmost part of the City of San Diego) to Oceanside (northwestern most city in the County). To give you some frame of reference, we're three times the size of Rhode Island, and almost the size of Connecticut. If you throw in Imperial County and Temecula, and its a pretty insane area to cover.
Now, if you're in the mood to drive A LOT, just ask in general where to go. But if you don't want to drive A LOT, specify the areas where you want to find someplace to eat. And don't worry, most of us are locals, so if tell us where you're staying and how far you're willing to drive, we can work with that.
2) While San Diego ain't Chicago or New York, we do have a fair bit of diversity here, and so if you're looking someplace to eat, specify the genre or genres you're interested in. Now, there are a few areas that San Diego doesn't do so well (like Jewish Delis), and a few that San Diego does extremely well (tacos, beer, farm to table), so don't be surprised if we steer you away from getting a pastrami sandwich. We mean well.
3) If you aren't sure where you're willing to drive to, or what type of food you want, tell us something about where you want to go. Are you interested in a beach setting? Young crowd? Good cocktails? People watching?
If you follow these suggestions, and the suggestions posted below, you are certain to have a good trip in my beloved home of San Diego.