Football, not even close. I'm surprised so many are voting basketball.
Kentucky has been and always will be a basketball school. But if UK were to win a championship in football, which is as likely as me winning the lottery, you're talking about beating Bama in the SEC title game, beating the likes of Ohio State/Oklahoma/Clemson/Oregon etc in the playoffs....I mean, that would be unbelievable. I don't think there has been a team to win their first title in the past 25-30 years in football so there's no parity. If a traditionally bad football school like us won it would be touted as one of the greatest championships of all time purely from an underdog perspective.
Football is still king in America, I'd love to see UK at the top of that mountain instead of a mountain we've been on top of many times and will likely be on top of many times in the future. That said this will almost assuredly never happen as the talent gap between the top 4 football schools is so big, but man...just imagine beating Ohio State in a championship game. Would never forget it.