Some friends and I are planning on going on a 2-team road trip for the 2013 season and realized that starting next year, inter-league play will occur all season long, so basically any potential road trip is on the table. What would be the best possible 2-3 team trip (in theory)? I realize that only a couple of these will happen next year.

San Francisco/Oakland
LA/Anaheim/San Diego
Chicago (White Sox and/or Cubs)/Milwaukee
Houston/Texas
Detroit/Cleveland/Toronto
DC/Baltimore
Mets/Yankees
Other?

I'm kind of hoping one of the California trips work out, especially if an AL team is involved.