Late War German stuff is, generally, the best with a 10 minute duration and a 5 minute recharge. I seem to recall that the La-7 and Tu-2 also have those numbers. The Ki-84's ratio is just as good, but its duration is only 1.5 minutes.
The RAF birds are the worst with 5 minute duration and 15 minute recharge rates. American stuff is 5 minutes on, 10 minute recharge, even on Merlins where the RAF has a 15 minute recharge.