http://forums.pelicanparts.com/showthread.php?threadid=218203
Maybe this thread will help. I was in the same position a few weeks ago...well without my parents.
I can tell you without reservation that San Diego ROCKS!! So much so, I'm moving out there possibly as soon as May 25th. It's that nice. I'm in Boston (newton is a suburb) now, and while Boston is amazing SD has a charm all of its own. Yeah, the weather was absolutely fantastic (for me that was not the great selling point). If you're over 21 (or have a great fake ID) there's tons to do...and when I say tons...I mean girls everywhere. I was pleasantly suprised (hope I spelled that right). It wasn't like there were that many girls who broke the mold, it's just that the median was much higher.
I wasn't into the touristy stuff so I can't help you there. I spent most of my time getting blown out (east coast for drunk - actually Bay Area) with the locals. I felt I could get a better feel for what the place is about that way since I was/am considering/almost have moved there.
So, to summarize: There's plenty to do. I think you'll have a hard time not enjoying it.
Highlights:
La Jolla was pretty sweet. Imagine if the world was given to you from birth - you'd have grown up in La Jolla.
I took a trip to Mexico - Salsapuedes - very pretty.
Gaslamp quarter (after a game at Petco Park. Anna Kournakova threw out the first pitch - how sweet was that!! Yes, she's very hot from the first base line). I found to reminiscent of Boston which I liked.
Pacific Beach - girls, girls.
Ocean beach (I think - I was kinda' sober while I was there - hahahaa) was pretty sweet. Went to a few places on the beach which were cool. Had awesome fish tacos. And I do mean awesome.
I went to a bunch of other places as well but really don't remember since I was pretty much led around by my tour guide/girlfriend.
Best of luck.
Oh, didn't make it to TRE - that's next though!