Greatest/Worst vs. Favorite/Hated Heel and Face Turns

I thought this might make for an interesting topic for the blog, given recent events involving CM Punk: what do you consider to be the greatest (in other words, the best executed and/or most significant) heel/face turn in professional wrestling history and the worst? Also, which heel/face turn would you consider a personal favorite (whether or not it did anything for business) and which did you absolutely hate with a passion?

Oo, fun list!
Best executed:  Paul Orndorff on Hulk Hogan.  Made sense from a business standpoint (#2 face upgrades to #1 heel), made sense from a storyline standpoint, drew MILLIONS of dollars in house show revenues alone.  Turned me into a fan for life.  Secondary honors go to the Midnight Express for making the Dynamic Dudes look like the gullible rubes we all knew they were.  The best ever face turn was clearly Virgil in 1991.  
Worst executed:  British Bulldog on Diesel in 1995.  Made no sense because they had no prior interaction, set up a title match that no one wanted to see and ended up being one of the lowest-bought PPVs in history, took a career midcarder in a loser tag team and suddenly we're supposed to buy him as a main event threat?  Epic fail all around.  Secondary honors go to both times that Billy Gunn turned on his tag team partners and failed as a single (Bart Gunn in 96 and Road Dogg in 99).  Worst face turn would probably be Randy Orton in 2004 because he looked like a weenie and it accomplished nothing.  
Favorite:  Barry Windham joins the Horsemen in 88. My friend was in TEARS when we were watching.  Also, Flair turning on Sting at Havoc 95 has gained momentum with me over the years to the point where I now love it and all the little nuances associated with t.  
Hated:  Mabel's turn in 95.  We all knew what was coming and there was nothing we could do to stop it.