San Diego is a fantastic place, so it’s a real shame that most tourists never think of going there (and visit Los Angeles and San Francisco instead).
So what are the best places to visit in San Diego? The city is basically divided into 4 main areas. These include La Jolla (which is in the northwest), Pacific Beach (just below La Jolla), Ocean Beach (just below Pacific Beach), downtown, and the park area. For tourists, I would recommend staying in the center or on one of the excellent beaches. The good thing about staying downtown is that public transportation is so good that you can get almost anywhere in an hour (at most).
Deep in the heart of downtown, between 4th and 5th streets, is an area known as the Gaslamp District. Formerly the red light district, this area is now the trendiest place in the entire city and boasts a great selection of clubs, bars, and restaurants (including the infamous Hard Rock Cafe). It is known as the Gaslamp District because the old streetlights used to be gas lamps.
If you have time for a day trip, I recommend heading to the upper class area of La Jolla. There are some great beaches here (some with live seals!) and some great snorkeling spots for the more adventurous.
The bottom line is that San Diego is a great place to visit, and if you’ve never been, you should definitely give it a try and go!