I haven't, though I'll get it eventually. I'm a big Grant Morrison fan, but missed a lot of his DC stuff over the years (with the exception of All-Star Superman and Superman: Red Son since I'm a big Supes fan) because I mostly read Marvel.

I can't recommend getting Y: The Last Man enough though when you can. It's easily up there as one of my favourite comic series ever, along with titles like Watchmen and Sandman.