AUBURN / ALABAMA War
All the rivalries mentioned certainly deserve serious consideration.  However, anyone who has ever experienced the IRON BOWL or anyone who is truly being honest with themselves understands that there is no rivalry that is in the same quadrant with the AUBURN / ALABAMA War.  No other state can claim the dynamics of what rides on this game more than the state of Alabama.  The IRON BOWL is the state's one sport wrapped up in 3 hours of hate and contempt.  Families align on one side or the other, period..the end.  It took an act of the Alabama State Legislature to force the two teams to start playing again or face losing funding for their perspective schools - A dispute around the turn of the century over tickets caused the 20+ year boycott.  They hate each other with every fiber of their soul and they always will until the end of time.  The fans on each side hate each other so much they won't even make eye contact at the game.  There's no fighting - like Florida rednecks at the UF / FL St. game; there's no taunting like the Ohio St / Michigan game; there's no agenda like Notre Dame vs. whoever game...  The bottom line is the IRON BOWL is without a doubt the most bitter, fierce rivalry of all time and people in the state take their week vacation to begin tailgating on the Tuesday before the game.  Campers and RVs start rolling into town the Sunday (6 days before) the following Saturday.  Don't take my word for it...ask anyone that has ever been fortunate enough to attend one of these games.  Scalpers have reported selling tickets for as much as $2,000 a piece and in 1989 there were 15,000 fans outside of Jordan-Hare Stadium that couldn't get in because of the sellout.  With 7:00 minutes to go, AUBURN opened the gates and for the remainder of the game AUBURN's 86,000 seat stadium had well over 100,000 people in it (15,000 fans lined up and down the isles).  There's not another team or Fire Marshall on this planet that would allow that to happen.  With all due respect to all the others...sorry, you're not even close.

Where's the Army Navy rivlary?

Any sports rivalry that doesn't list Army/Navy is pitiful.  Sports rivalries are not that the championship is at stake, they are not who votes the most for the rivalry, they are not based on attendance or money, the rivalry is about what is left on the field and what it means in the future. The jets that defended our country as we reeled from the 911 attacks had players from the great rivalry.  The units in Afghanistan have men from that rivalry.  For a country where the almighty dollar fuels everything from Bucks football to ESPN polls, the meaning of the Army/Navy game is escalated far above money, wealth and fame.  These men will hold the same places in our hearts as George Washington and George Patton.  They left it all on the field and it was not for money.  It was for their academy, their service and their country. Shame on you for not listing Army/Navy!
Edward R. Duffey

 
USC vs. Notre Dame.

Impact: More national championships, more Heisman winners, more glamor

Differences: region vs. region, style of play vs. style of play, image 
vs. image

What other rivalry has had two great eras with two great sets of 
coaches fighting each other at the same time when both were at the top of 
their game?

Rockne vs. Jones

Parseghian vs. Mackay

FLORIDA VS. FLORIDA STATE!!! GO FLORIDA,
THESE SCHOOLS HATE EACH OTHER AND FIGHT W/ EACH OTHER
 Anthony

Florida vs. Florida State, it aint even close, this is the best one ever!!!
 They even fight, before games these schools hate each other!! They should be Number 1!!!!!!!
Anthony
Georgia vs. Georgia Tech
Seth
 

Clemson  vs.    Carolina
                        Tigers         Gamecocks
 
By far one of the biggest rivalries in college football is the Clemson- Carolina game.  Not much else compares.  These two schools have an almost endless hate for each other.  When Clemson was a military- agriculture institution, somewhat like Virginia Tech was and Texas A&M is today, the Clemson cadets would march all the way to Columbia each year for the big game.  One year they even fixed bayonets on some heckling gamecock fans.  To the people of South Carolina, Clemson- Carolina is a year round religion that can at sometimes break up families.  Clemson- Carolina is like no other rivalry, and anyone who has experienced it will testify the same whether they are a tiger, a gamecock, or just don't care.  
                                    Adam Byerly
                                     Inman, SC
                              GO TIGERS!!!!

GThomas writes:The Ohio State University -vs- those people up north (michigan).
This is clearly the greatest rivalry of college football.  No other is as long-lived, traditionally, with the same sort of conference and national importance decade after decade.  I know many in Ohio who remember dates of birthdays, anniversaries, etc., in relation to the OSU-Michigan game of that year.
(e.g., My grandfather, my brother, and I were all born in years where OSU finished undefeated; but my brother was blessed to be born the year OSU went undefeated and destroyed Michigan at Anne Arbor 50 to 20, and then graduated from high school with OSU again going undefeated and winning at Anne Arbor 18 to 15.  The entire family knows this, believe me!)

 Ohio State- Michigan
 darrgrej

BUCKS - MICH  no question

arguably, greatest rivalry in SPORT   GO BUCKS!!!!!

mich and osu, XAVIER

 Alabama vs. Auburn:
There's none like it. Unlike other rivalries, this is a football game that every fan looks forward to every year. Either team could have a
winning record and the other a losing record and the only thing that matters at the end of the season is, "Did we beat the other school in
this state?" That's the only question that is asked. Conference titles, national titles, 10 win seasons, individual player awards; none of this
matters unless you beat the "other" school. The schools are even on opposite sides of the state. UA being on the west of Birmingham and AU
being east of Montgomery. Children are born into the respective fan bases. The succession of children attending either university is
inherent to the family. There is nothing else like it. It is an experience unlike any other. In this state, football is the tyrant king, and every person must align themselves with their teams, because at the end of November, the wait is over and the ONLY game that matters is played.