If the Broncos had lost their first playoff game like they lost to New England, he would have gone to Denver (I proposed this months ago, in the football smack-talk thread).
Since they made the playoffs and beat the Steelers, I've got to think they're committed to Tebow for another season, though (although if anyone has the cajones to drop Tebow for Manning, it's Elway).
Miami makes the most sense; good D, Brandon Marshall to throw the ball to, good running game (at least later in the year), good weather, he's already got a home down there.
Denver would be a helluva good fit, but I just don't see how they'd deal with the PR nightmare.