+1 if hills are an issue. This is probably the flattest century ride in S. Cal, about 1500 ft. I will be doing the 1/2C again this year (with option-I plan to detour up Torrey Pines-Genesee I5 tot he Sorrento SAG to add some climbing). The full Century is just two laps of the 1/2C, which makes it less popular among century junkies. The event is one of the nicer ones I've done in terms of the food options and party like atmospere.

This one in October will be my first full C, and it's pretty hilly http://ridetvc.com/ The food is from just one source, but it is good, though I had issues with the service last year.