Houston owner Bob McNair recently suggested the addition of "regional rivalries" if the 18 game schedule (minus two pre-season games) goes into effect. Bob obviously wants to cash in on the Cowboys popularity, but it does make sense, why not have Houston vs. Dallas every year? Why not have a "Battle of the San Francisco Bay" every year? St. Louis vs. Kansas City "I-70 game" etc.
Where this gets problematic, is what if your natural rival is in your division? Green Bay & Minnesota already play each other twice. I think you would have to eliminate Division games from this. In fact, it probably would work best if it was inter-conference games. Personally, I think this would be a fun addition, and instead of adding a week of regular season, I would make it 17 weeks, and add a week of playoffs, increasing the number of teams that get in. Anyway, here is a map of the current NFL teams. I'm going to attempt to list the "rivalry game possiblities"
Here goes my attempt to identify what geographical rivalries would be:
San Francisco vs. Oakland - this rivarly should be played every year.
Seattle vs. Denver - Former AFC West rivalry renewed
San Diego vs. Phoenix - what LA doesn't have a team? OK San Diego will have to do
KC vs St Louis - the 85 World Series shouldn't be the only thing St Louis has to complain about
Houston vs Dallas - Battle for the Lone Star State
New Orleans vs Cincinnati - Who Dey? vs Who Dat?
Tampa Bay vs Miami - With three Florida teams, have to pick the two furthest South
Jacksonville vs Carolina - Battle of the Teal expansion teams
Nashville (Tennessee) vs. Atlanta -
dirtiest team according to Kyle Orton vs. dirtiest birds
Washington vs Baltimore - They share an airport
New York Jets vs Chicago - Chicago pizza vs New York pizza
Pittsburgh vs Philly - Pennsylvania bragging rights
New York Football Giants vs Boston (New England) - Yankees vs Sox, revisited
And now the hardest part, from a geographical standpoint, seems to be the AFC North/NFC North
Buffalo vs Green Bay - who's frozen tundra is colder? Buffalo wings vs Cheese
Cleveland - Detroit - Motown vs Rock n Roll
Indianapolis - Minnesota - which indoor stadium is the loudest?
Other ideas are teams that moved, i.e. the Houston Oilers ( Tennessee Titans ) could play Houston, the purple Browns (Baltimore) could play Cleveland, the Los Angeles (St Louis) Rams could play the Los Angeles (Oakland) Raiders , the Dallas Cowboys could play the Dallas Texans ( Kansas City Chiefs ) - but I don't think the NFL would want to highlight that some teams have screwed over their fans, so this facet is probably not realistic.
I tried to stay with out of Conference rivals. Who would you want to be the Chiefs rival? What say you?