Longest I've ever played:
Par Three: 240 (13th(?) at Seaview)
Par Four: 500 (12th at Bethpage)
Par Five: 640 (14th hole at Jericho National Golf Club in New Hope, PA)
I think the 16th hole at Carnoustie stretches to 250 for the Open and it's a Par Three...
Personally, I felt the 640 par five was just too much... You wailed at the ball for two shots, and then had a fairly interesting long iron approach. However, if any of your previous shots weren't executed PERFECTLY you were staring at double bogey or worse.
I liked the 12th at Bethpage (probably because I carried that bunker from the tips)
As for the Par 3 at Seaview... the green was huge and very fun to putt on, so hitting 3-wood in didn't bug me one bit.