For attention spans less than 8 hours you can try American Football.
For starters, the name "football" is something of a misnomer, because kicking the ball is not part of the general flow of the game and it played primarily with the hands not the feet. A full game lasts about 3¼ hours, although the game clock only runs for an 60 minutes, and on average the ball is only in play for about 10 minutes!
Yeah, I watch it occasionally.
It's particularly amusing to watch it when a team attempts multiple lateral passes - the crowd and the commentators go bonkers. Yeah, they do that all the time in rugby league and rugby union. It's called catching a ball - something you don't actually need a baseball mitt for.
Back in the early 1990s the Australian ABC started a late night show of highlights from the previous weekend's games, with the show hosted by American ex-pat entertainer Don Lane. Lane did a good job of explaining the game and its rules and tactics without talking down to the audience, and (in those pre-Internet days) answering letters from viewers.
That, when they were perennial cellar-dwellers and seemed to have the ability to lose a game from any position, was when I started supporting the NE Patriots.
However, I don't let that stop me from enjoying it, because I understand what American Football really is; not a ball game between two teams. but a game of chess between two coaches.
Personally I prefer it as a card game:
http://boardgamegeek.com/boardgame/71889/third-and-long-football-card-game