I'm going to start traveling frequently for business from either San Francisco or San Jose CA to Atlanta, probably once or twice a month. Trying to find which airline will offer the best rewards. I'd like to build miles for personal travel redemption. But with the program changes in Delta and United, I'm not sure which way to go.

I think my top contenders are United, Delta, and Southwest. I like Southwest, but the only thing that makes me hesitate is I'd like to use our reward travel for Hawaii, which Southwest doesn't fly to. But this isn't a deal-breaker since we fly other places too.

Some notes:
-I can fly out of either SJC or SFO, but would prefer SJC since it's much closer to me.
-Prefer direct flights
-Will fly coach mostly, but I have the option to upgrade when reasonable.
-Currently do not have a credit card tied to any airline or any other bank of points with any specific airline.

So which airline would you pick?

Thanks in advance.