I personally will think it the greatest show ever if Jesse kills Walt and finds some kind of personal redemption, makes some kind of massive score and gets the hell out. I want Jesse to 'win' breaking bad.
Are they done with the cancer thing? Wouldn't really like a relapse situation killing walt. Think it was good to get him motivated to start and I like that he's 'well' now and can never go back.
I thought the last we heard about it was that it was relapsing.
I think Walt dying alone of cancer after everyone abandons him, still believing he was a hero, is probably the most poetic ending, but it might be a little too dark. I'd take Jesse killing him as a runner up.