Another vote for WN. its such a short flight, you wont care to be upgraded to 1st much. WN ... so many flight options.
Btw, to the extent you can, AVOID SFO, and use OAK.
SFO = notorious for delays due to fog.
OAK = one of the easiest in and out airports in California.
I used to fly LAX to Bay Area weekly for 3 years... the few times I had to switch to SFO or SJC, I dreaded it.
On the other hand, if your goal is to accumulate status on another airline for the purpose of international reward redemption, AA would be my choice