I left my kegerator at 34 for my Pilsner and it was ok, but almost tasteless(what I was going for(its for a party)) But at that temp my hefeweizen and my IPA were blah.
Stouts seem great at about 48
My IPA is great at 52, but most people, other then us, dont like it that warm.
I tend to like my beers at almost 55 for the most part with the exception being my lagers and specialty flavors (rye, rauche) which I do like colder.
But yeah, as previously said, Heavier=warmer