United and American Airlines have round-trip flights from Phoenix (PHX) to San Francisco or Denver (SFO, DEN) for $110-$135, NONSTOP. Flights October to March. Weekends available. Origin/Destination reversible.
A Carry-on bag and also a personal item is allowed for free on American. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.
These fares will probably expire tonight at midnight. Which is the same time that the Southwest fare sale ends.