While a majority of my knowledge centers around debian, there are many distributions and some of what I know is a bit wider reaching.
I have installed and used these distributions for periods greater than 3 months:
I have also tried roughly a dozen alternative distributions, but usually not long enough to make an assessment.
If I had more time, I would be inclined to try arch again, only because I found it to be a fantastic experience that trumped even debian. However at the time bad RAM led to instability and a fresh install, and I wanted a system that more closely matched the servers I was writing code for at the time. Having switched to a compiled-code preference (golang), I bet I would be very happy with arch.