It's probably changed for me over the years, which has everything to do with getting older. But that doesn't mean it's any less enjoyable.
My routine now is part of the fun for me. I've generally got Saturday mapped out. Early breakfast out someplace, bacon and eggs, coffee (decaf these days), and there's always an ample supply of deli items on hand to get me through the rest of the day. Then just non-stop viewing with as little interference as possible. I think it's important to watch as many games as possible, as while stats are meaningful, giving teams the eye test is huge for me. This is why I don't like watching games at a book, as I'm just not able to concentrate there.
The money involved is obviously important, but it's the action on the field and the regular weekend football routine that makes it work for me. So I have no problem getting just as revved up for a game I'm not betting on as one that I am.
Most fun thing? Breaking down a game, even one where I might not have found an edge that made it worth a bet, and then watching it play out almost like I had a copy of the script. But it's even better if that happens and I'm on the right side!