Me too. How about something I just invented: A nice single player campaign, but at certain branches in the story, you have to go online and earn kills or points or other stats. Then you take those statistics back into the single player adventure, and proceed along whichever branch you've earned. 
What the hell is this idea? I was just talking about a game at it's most classic being. A great single player campaign also where the game features multiplayer. Then again i did like one thing which was sort of the opposite you were talking about man.
The opposite is where you have to play the single player campaign, and through this is the only way to get upgrades and power-ups to customize your vehicle, ship, mecha, in multiplayer. I liked this idea when the game Axis featured it. You played as a mecha you could build and swap out parts and customize your weapon loadout, it was a fast paced first person shooter utilizing the x, y, and z axises. Anyway, in order to get more parts and weapons for you mecha in multiplayer, you had to play the single player, and after you won each round, the mecha that you defeated you get its part and weapons that you can customize on your mecha in single and multiplayer. Anyway it worked out great. That was actually a game i liked the multiplayer a lot more than the single player.