DawgNDuckfan, tough call on rivalries. Have to go with Duke/UNC. With the new coach at UNC, can this rivalry get any uglier? Probably the best in the country?
Honest question: if you visited Asheville, NC, how many UNC fans would you find and how many Duke fans would you find? I'm sure you could find some UNC fans living in Asheville, but could you find any Duke fans there at all?? ??? The reason I'm asking this is because the Alabama-Auburn rivalry extends beyond central Alabama into north and south Alabama. Dothan, Alabama is very far from both the UA and AU campuses, but you can still find a lot of passionate Alabama and Auburn fans. Can you say the same for UNC-Duke in Asheville, NC? (which is very far from Chapel Hill or Durham). I'm not saying that UNC-Duke isn't very passionate in the Raleigh-Durham area or isn't very passionate among the players. However, I just don't think that the whole state could be divided into just UNC or Duke fans.
Best rivalries by conference:
SEC: agreed Auburn/Alabama
Big 10: agreed Michigan/Ohio State
Pac 10: USC/UCLA and runner up Stanford/Arizona BB
Big East: Pitt/WVU
Big 12: Oklahoma/Texas
Slightly disagree on the Pac 10. Arizona-ASU is the closest equivalent to Alabama-Auburn out west. I don't think it's as publicized as USC-UCLA, but it's a biggie too.
Another big rivalry in the Big East to me is Miami vs Syracuse. It seems that you guys don't like each other at all.
Texas-Texas A&M is the runner up to OU-Texas, IMO.