Today I picked up a pristine boxed set of Planescape. I had a 40% off coupon for one item at the bookstore, so I actually got it at retail price instead of "collectible" price.
I love the art, the slang, the attitude of Planescape.
I think AD&D is totally the wrong rules set for it, but the setting is cool.
I like the sect/faction mechanics.
It's also the only setting where I will ever again abide the presence of aasimar and tieflings. Because, you know, context.
A worthy addition to my growing collection of boxed sets. Huzzah!