If it ships with an open or unlockable bootloader, you can put anything you like on it. This means pretty much any nexus phone, HTC phone or Samsung phone is good to go.

I've tried both Firefox os and Ubuntu touch on my galaxy nexus. I've also tried regular Ubuntu and Debian on my Asus transformer tablet.

That was much easier and cleaner and proper than it was getting my iPhone boot android, which relied exclusively on hacks, and eventually bricked it during a failed factory reset.