Where do you live? Avoiding a commute (or at least avoiding a difficult commute) is the key. That said if you were going to move in base I would.....

1. TSA (1. Because I work here 2. Good management/Pilot group 3. Growth/upgrade)
2. Endeavor (1. Highest Paid 2. Wholly owned 3. Lots of 900s 4. Future w/Delta?)
3. GoJet (1. New 900s 2. Fairly quick upgrade)
4. Republic (1. Fly 175s)

We are overwhelmed right now with all the growth right now at TSA. However, with your 121 time upgrade would be very quick for you here. If I had to make the choice between the 4 you listed right now I would choose TSA again, but only because I couldn't bring myself to move to any of Endeavors bases otherwise with the retention bonus it would be tough not to go to Endeavor (They weren't offering that when I was making my decision). Ive met a lot of GoJet guys that are good guys, but they will always have that reputation (similar to PSA right now) And just do your research on Republic. Morale is very low there for a reason.

I would also reach out to Compass and/or Skywest.