Wrestlemania 28 vs The Undertaker.
Better HIAC, Kane debuted in a HIAC match, although he's not actually a part of the match, it's still fitted that his last match would be a HIAC against Taker hmmm make that inferno hell in a cell jkesIt will have to be a Last Man Standing / Casket / Buried Alive / Inferno match though.
Amen brotherFor someone of his loyalty to the company and his role of putting other guys over without complaint, I think he does deserve a big deal made of his retirement.
However apparently (I remember reading somewhere) Glenn Jacobs doesn't like to be the big centre of attention, and plus his character isn't really one that needs big send-offs. People like Ric Flair and Shawn Michaels are entitled to big send-off speeches or parties because they portray human characters. Kane's character has always been just a monster with little human emotion who just likes destroying people. So having a big send-off for him would be unusual.
One thing is though... I don't think he should have a mask again for his retirement. He's been unmasked for nearly a decade now, as opposed to the 5/6 years he spent with it on. He didn't suddenly start to suck because he lost the mask, he just started getting booked as the "monster obstacle for up-and-comers" and of course, he's been getting older and that's always accompanied by a bit of a slow-down in terms of in-ring speed and general ability. I'm just glad he can still go in an enjoyable way.
As for what his actual retirement will be? I think there'll be some big thing, but it won't be a proper send-off like Flair, Michaels and, to a fake and stupid extent, Cena had, it'll just be one last big match with a massively theatrical exit.
Although I swear to God, if they ever do the "he went back to Hell" thing with his retirement I will find Vince McMahon and punch him to the floor.
EDIT: No matter how many people may hate the idea, I'm all for Kane and Undertaker retiring together next year after their final Wrestlemania match.
This actually seems very likely.He will go on a monster heel run, destroying everyone in his path, like a 9 month unbeaten run,even Super-Cena (GOD FORBID!!) and he claims to be able to beat anybody. and Taker will come out (whether this be before WM28 or WM30, and announce that he wants to face his brother and he wants to end Kane's streak, while for Kane's streak to continue he has to break Taker's WM streak. They have a great match at WM, then they both retire on the same night.