I would prefer less interleague games and more divisional games. With 15 teams in each league, there will always be at least one series, but it's hard to get excited about playing the Reds or Marlins.
I'm rather see them play games that will have a greater impact on who wins the division.
MLB would hate it and it would never happen but 30 games against divisional teams, 3 games against each of the other AL teams and 12 interleague games. I'm sure it would hurt financially but I'd like to see it.