Obviously Utah is our main rival, regional, etc.
But most teams end up with a conference rival too. I thought coming into the conference it might be Baylor, but they hadn't stuck.
The hate and vitriol and overall trashiness coming from ASU including their coach, players, and fans, has pissed off our entire fan base and all our players. Reports from fans at this game were 10x worse than BYU fans attending the Utah game (Utah fans seemed subdued due to their sucky season to be fair).
If BYU meets ASU in the CCG (this is my ideal scenario), then this conference rivalry will be set in stone in my opinion.