The zipper is the only thing that really works, IMO. Just do it already.
I'd be alright with going North/South, but splitting up the state of California for media reasons.
North: Washington, Washington State, Oregon, Oregon State, Cal, Stanford
South: Colorado, Utah, Arizona, Arizona State, USC, UCLA
If we had to go to 2 paired rivalry games (with the other 4 cross-division games rotating) in order to make the California schools happy, then that could work. I'd take annual games with either Washington/Washington State or Oregon/Oregon State along with a 2-out-of-4-years setup with the other cross-division teams.
The Oregon and Washington schools might have a gripe with this setup, though. They would only play in LA 2-out-of-4-years while everyone else got an LA trip every year.
What's cool with the modified zipper that includes the regional pods/2 fixed rivals is that it satisfies everything except for it being easy for a casual follower to understand the divisions. That branding of divisions is somewhat important, but I don't think it's as important as competitive balance, regional rivalries, and recruiting fairness.
Modified Zipper (what Larry Scott calls the "Hybrid") goes as follows:
California POD: USC, UCLA, Cal, Stanford
Mountain POD: Arizona, Arizona State, Colorado, Utah
Northwest POD: Washington, Washington State, Oregon, Oregon State
Divisions split based on east/west relationship of the natural rivals.
West: UCLA, Oregon State, Stanford, Washington, Arizona State, Utah
East: USC, Oregon, Cal, Washington State, Arizona, Colorado
9-game conference schedule includes 7 fixed games: 5 divisional opponents + the 2 regional POD opponents in other division; other 2 conference games are on a 2/4 year rotating basis versus the remaining teams from the other division.
For CU, it would look like this every year:
USC, Oregon, Cal, Washington State, Arizona, Arizona State, Utah + 2 from UCLA/Oregon State/Stanford/Washington.
The great thing this does is that it gives everyone an LA team in its division, which means 2 trips to LA every 4 years. Then, with the cross-division rotation, everyone also gets at least an additional 1 trip to LA every 4 years from that matchup. So, everyone is in LA 3/4 years (and every other state/region too). It's a bit complicated, but the numbers work out perfectly. And it's also a perfect format for expansion to 16 teams since the pods are already in place. If the Pac-12 becomes the Pac-16 through the Mack 10, it can put TTU/UT/OU/OSU into a Southwest POD and pair it with the Mountain POD in order to create a division.