United and Delta are my majors.

I don't care for United a whole bunch, but with the limited notice I usually have they have the schedules and locations.

Delta is preferred when I can use them.

I have both airlines top CC's and rack the miles and credits at an embarrassing rate.

I try to keep the miles in the bank for our vacations, then gift a bunch to Deb and upgrade to first for our longer trips to say Hawaii or Cleveland.