EWR has the best flying and best seniority (junior). People avoid it because of the cost of living and it's in Newark, NJ. The pilots I've flown with the last 12 years in EWR don't live there (maybe one or two do). Nearly all of them drive from surrounding states or commute from where ever they want to live. Crashpads are popular too. I've never had a crash pad. I've commuted or driven (I now live 1.5 hours away in PA).

As a new pilot:
You will be on reserve less in EWR.
You can hold any plane in EWR: 737, 757/767, and 777.
You can fly domestic or international.

CLE is only 737 and you will find it hard to get in there. Plus, the weather sucks.

GUM is only 737 and you fly red-eye round trips without overnights. It's senior becasue it's small and full. Expensive too.

IAH is in Texas and that's about all I have to say about that.