Headed to LAX 12/25 - 12/31. Want to see LA, San Diego and parts between. Need some suggestions for hotels, sights, and romance on the way...

For romance on the way... is it Hollywood Boulevard?

Will you be driving south? What kind of sights are you interested in?

Was recently in San Diego for the first time (LOVED IT). I'd suggest staying on Coronado island (the Hotel Del if you can swing it) or in La Jolla. Take the tram ride tour ($24) that takes you to Balboa Park (the ZOO, botanic gardens, museums), Gas light district, Old Town, La Jolla, Coronado etc.

you really need to be more specific in telling us your interests, do you have a car, hotel prices can range from $50-$1000 - how much do you want to spend. tell us more so we can help you.

I will fly into LAX, rent car then head to Santa Barbara for a day or so, then to San Diego for several days. Would like to stay in La Jolla or Coronado, need some hotel, romantic restaurant recs. What to see and do in Santa Barbara and SAN?

Check out the Hotel Parisi in La Jolla or the Hotel Del Coronado. People also like the Loewe's on Coronado but I didn't see it so can't compare it to the Hotel Del.

If your budget is not not restricted, the Four Seasons Biltmore in Santa Barbara might suit your quest for romance. Spanish ambiance and old fashioned. Some claim that it's not quite worth the money- but I think it has atmosphere and class. It is a building dating back a few decades (1920s, I should guess), so there are some compromises regarding the room standards- but still!
I cannot judge on Hotel Parisi in La Jolla, but mclaurie's advice regarding the Hotel Del in Coronado is certainly spot on. BTW this is also a historic property that comes at a price and again some people claim it is not worth the money. But its location is picture perfect: right on a beautiful beach. Also lots of charming atmosphere although during days it can get a little busy with outside visitors taking sightseeing tours of the hotel. They also have a newer section called Ocean Towers which is a bit more generic. I still love the place.
I would also advise against the Loews on Coronado. While the hotel may be quite lovely, I do not appreciate its location. It is not on the beach side of Coronado, but on the bay side. And it's some 5 min. by car outside the town of Coronado- a bit in the middle of nowhere. Unless you can cut a deal there, it would not be my preference.
Also a lovely place might be L'Auberge Del Mar in the laid backk beach community of Del Mar just North of La Jolla.
Try dinner in La Jolla at George's at the Cove and breakfast at Brockton Villa.
Should Santa Monica be an option, try the Fairmont Miramar. A historic hotel that's been kept immaculately up to date.