We spent 3 days in Santa Barbara last summer after a few at DL.
We really liked the Santa Barbara Maritime Museum. It's a smaller museum, but very well done. We found a Groupon, but even at full price, it would have been worth it. We also did the lookout area at the Santa Barbara County Courthouse in downtown. The inside of the courthouse has a lot of beautiful art and features, and then you take the elevator to the top where they have an open area that gives you 360 degree views of the town, marina, and mountains. Definitely worth the stop.
We also took a day trip out to one of the Channel Islands National Park sites with Island Packers ferry service. It wasn't cheap, but it was absolutely the highlight of our time in the area. We chose the Scorpion Ranch landing area of Santa Cruz island. The views were incredible, as well as the native fox that we got to see up close.
We also did a full day scenic drive up into the mountains and surrounding areas. That again was a fantastic day that even our 15-year-old son enjoyed. We went from Santa Barbara to La Purísima Mission State Historic Park, Solvang, Santa Ynez Valley (including stopping at the Santa Ynez Valley Historical Society Museum and Carriage House), Cachuma Lake Recreation Area, and Chumash Painted Cave State Historic Park.
If you have any questions about any of this or want more info, just let me know. Thanks and hope you enjoy your visit!