Which Phone YOU would recommend for Android 6 Custom Roms?

Hey Guys,

at the moment i got an S6 but thanks to the Exynos CPU we would be able to have much fun with AOSP, CM- Roms

Which from these Phones u can recommend me or which phone has the most Users/Developers?:

HTC One M9
LG G4
Sony Xperia Z3 Plus (Z4)
Samsung Galaxy Note 4 (Snapdragon)

All phones would be Unlocked.
Thanks