I get up to SB a lot as my daughters went to school at UCSB (one still there).
Los Agaves is fantastic. There's one downtown SB and another in Goleta. Just really good food, nothing pretentious. For a dive joint, La Super Rica Taqueria is great. We go there every time before concerts at the SB Bowl. Get the Super Rica Especial. Trust me.
http://www.yelp.com/biz/la-super-rica-taqueria-santa-barbara
Lily's also good for Mexican.
Mac's Fish n Chips was on Diners, Drive Ins and Dives. Looks legit.
http://www.macssb.com/
Sand Bar also a good option. Globe really good for drinks and small plates.
Hang out on State Street in Santa Barbara. Funk Zone on Lower State.
Also, if you're into wine and in town the weekend of Oct 10 the Santa Barbara Harvest Festival is going on. Awesome. 100+ wineries, top chefs, phenomenal day. We'll be there.
http://www.celebrationofharvest.com/festival.html
The Bacara is fantastic for a brunch or something. Great setting. Speaking of the Santa Barbara Bowl - check out concerts on dates you will be there. Bummed I'll be in DC next week or I'd see Don Henley there on 10/7.
Jeanine's also good for breakfast/brunch.
Good beaches - Butterfly Beach (across from Biltmore Four Seasons in Montecito) and Hendry's (where the boathouse is) + West Beach by the pier are good beaches to hang out.