I don't like any of these options. I don't like COMPETITIVE multiplayer AT ALL. I do think that it's nice to have some kind of co-op multiplayer in SOME games, but it's not NECESSARY. And "sure, as long as it's done well" is silly.
So, my choice is: I prefer co-op multiplayer, when it's appropriate to the game, but I can live without it.
Edit: Oh, and "appropriate to the game" means that the game isn't based around something that makes multiplayer absolutely suck, like exploration or story. Shooter, multiplayer is appropriate. Racing game, multiplayer is appropriate. Sandbox game? Hell no. RPG? Maybe, probably not. Mission-based tactical combat? Hokay. RTS? Hokay. Turn-based strategy? Er, maybe, I don't play them.