Not to take away from anyone here, because there are definitely a lot of smart people on this board in a wide range of fields. But besides a small handful, Part 121 aviation is not this groups forte. If you want an actual answer to your question, I’d suggest you go here:
https://www.airlinepilotforums.com/regional/
I heartily second this.
For the OP, sit down, start reading, and
take the time to begin to understand all of the forces that determine what a good vs bad regional would be to work for. Many of those factors -- commutes/bases, pay, scheduling, upgrades, flow, etc -- have been mentioned in this thread, but which mix of those factors is best for you is an answer only you can provide. Plus, there are more that you may never have even thought of that might pop up in all that research.
As mentioned those factors are changing all the time at every single regional. What is true today may not be true tomorrow. The regionals that were the vogue destinations when I was working at one are both in the crapper currently, and some that were written off and never to be heard from again are now popular and thriving. So, be careful what advice you listen to and beware from whom it is coming from. I've been away from the regionals for a few years, so outside of what I read on the forums and hear from newhires at my company, my knowledge of what's currently going on is just a bit stale.
So, do your research. Read what the pilots from each airline are complaining about on APC -- believe it or not, that's actually a pretty good means of detecting what the biggest problems are at each of the companies. It won't tell you much about what's "good" or "normal" (since the vast majority of the posts are people bitching about what's wrong), but it is a very useful means of comparison.
All that being said, OP, why do you tell us a little about what you're interested in doing long term, where you live, what the most important of the factors in your opinion is. Without knowing at least some of that, none of us can provide you with anything that might actually be helpful in an initial radar vector or two to start your research.