I thought the Capaldi era had a great cast suffering from mostly bad scripts. I haven't seen anything with the new lady doctor, so I have no opinion whatsoever there.
As for prior doctors, Eccleston deserved another season, because the first is always a sort of shakedown cruise where everyone is figuring out what works and what doesn't on the fly.
Tennant was great. Full stop. And Donna was his best companion.
I quite liked Matt Smith's tenure. The Doctor/Amy/Rory trio was a lot of fun. Much as I liked Tennant's run, I think Smith might take the cake as the best Doctor of New Who.