best Batman/Superman Graphic Novel?

[Shyft]

I have always loved The Dark Knight Returns, and a key factor in my enjoyment of it was seeing how Bruce and Clark interact and indeed fight. I have recently started picking up the Batman/Superman regular book, and am quite enjoying it so far. My question is, what should i look out for in terms of a Batman/Superman paperback tradebook/graphic novel?

[inthewayboy]

I can't really think of a better tale than the DKR...never seen a better match-up. And the fight is monumental...damn that was a good book!

A few others do come to mind though:

Trinity

It's about Batman, Superman, and Wonder Woman so you get an extra bonus. This is done by Matt Wagner, both story and art. I really dug the style, and the characters really mesh well in regards to story.

Superman: Red Son

More of a Superman book, but Batman still fits in very well here. It's an Elseworld (SP?) title that shows what might have been had Superman landed in Russia.

[Mike42]

I vote The Dark Knight Returns too.

[Kara Zor El]

Generations is an interesting Elseworlds spanning decades. It's a bit of fun more than a serious read.

[Kid Kyoto]

I also vote for Generations 1 and 2 (never read 3).