One of the very best of what I would call proper par 4s of a par 3 length is without a doubt the 13th at Stoneham. At one time I can recall detesting this hole, but now I think it is very clever. The diagram doesn't indicate the tee shot is blind over a wee ridge. This hole is very reachable especially in summer, but the visual clues on it send a mixed message. What the player can see are large trees left of the green and open ground out to the right. The natural instinct is to go right, but the best way in is from the left, but if you are going for the green you mustn't hoick it or it is in all likelyhood a lost ball. Go right and you have a near impossible approach over the bunker to a green that slopes away. This hole really is a great example of why blindness and protecting holes at the green can be very effective design elements.
Go to "the course" then click on the 13th hole
http://www.stonehamgolfclub.org.uk/Of course, any thread like this must include Kington's 18th - the best finishing hole I know of. Besides, photos of it freak out Mark B which can only be a good thing.
One of the coolest things about holes like these is that they mess with our often silly notions of par and what it should mean. I wonder if par weren't so all consuming these days if we wouldn't have more imaginative holes in which the distance compared to par is largely irrelevant.
Ciao