This question is kind of tricky to answer due to the fact that NFL rivalries tend to come and go, such as Indianapolis vs New England in the 00’s, while others such as Green Bay vs Chicago seem to last forever. So, I’ll just list off current rivalries and some traditional ones as well. Seattle Seahawks – This is not only based on division, but the fact that Seattle coach Pete Carroll and forme 49ers coach Jim Harbaugh were rival coaches in the college ranks as well at USC and Stanford. So, when these two teams meet, there’s often a great deal of hard emotion that boils over.
Baltimore Ravens- This also stems from the coaches. Jim and John Harbaugh, of course, are brothers and the son of a football coach, Jack. Who used to coach at schools such as Iowa and San Diego State. While this rivalry is more easygoing than with Seattle, it still elicits strong emotions. St. Louis Rams- Another division rivalry, but also one that has lasted since the Rams moved to L.A in 1946. While each team has seen extended periods of time on tops- the Rams in the 40’s, Niners in the 50’s, Rams in the 60’s and 70’s, the Niners in the 80’s and 90’s, back to the Rams in the 00’s, and lastly the Niners once again, it’s always a battle when these two teams collide.