Futurama has nailed two out of its four finales. "The Devil's Hands Are Idle Playthings" seemed impossible to beat, but holy shit, "Meanwhile" pulled it off.
Or a show that got better just before it was canceled. Entreprise is a good example of a show that was just finding its voice just before the end. Even on this graph, the last season has some lows, including the finale of course, but it's more consistent than the first seasons.
The thing about House is that it had been bad for 3 seasons (and that's being generous) before the finale. Does it really count as a bad finale if the series was already falling apart?
I absolutely loved that season. It was something fresh, a new way to see how Gregory handles the outside world without losing his wits when the chips are down.
I have to say "All Good Things" (the TNG finale) was pretty decent. Though the rest of season 7 just felt like they had run out of ideas and were raiding the reject pile from previous seasons.