I don't feel like we have any Tier 1 rivals. It definitely used to be Idaho, but that has been gone for quite some time, even before the Conference realignment stuff, and the Vandals having to return to the Big Sky.
We certainly have a lot of history with Nevada, and they are definitely a game that peaks interest when we play them, but even with that 2010 loss I don't get any intense hatred for them. And outside of message boards I never hear anyone talk about playing them as if it is any big deal.
Fresno doesn't feel like a Rivalry to me either, and we have way less history with the Bulldogs than we do with the Pack.
The BYU game is what it is, it's a nice OOC match up for us, and there is enough overlap in the fanbase, and they are close to us geographically that it gets quite a bit of buzz considering they aren't even in our Conference and the games don't really mean anything in the big picture.
I would honestly like to see a Rivalry develop with Utah State. I think they closer to us than Nevada is, it's an easy drive, the program has really solidified since they joined the MWC, and the fans are passionate. Seems like they will get to be a bit more on our radar if they stay consistent.