Well this is just incorrect. "Couples who bring their baby" should be the undisputed and immovable holder of the #1 position. There is nothing, nothing that some bald, toothless little hellspawn stuck in "unearthly screech" mode cannot ruin. No matter how great the noise, a baby's wail can cut through it like a hideous, ragged scythe.
Then, of course, everyone at the party who just loves babies (which will invariably be EVERYONE BUT YOU) just has to take turns holding it and fawning over it and making nauseating smoochy-poo noises and saying inane things like "Awww he/she looks just like you" NO IT DOESN'T LOOK JUST LIKE THEM ALL BABIES LOOK THE SAME AND THAT IS NOT REMOTELY SIMILAR TO ANY ADULT HUMAN IN THE WORLD ANYWHERE ARRRRRGH.
OK, now I feel better. Don't worry folks. Parenting is not on my short or long-term agendas.
I don't necessarily agree that the "Guy who gets wasted" will ruin a party, though. I know someone like that and his inebriated antics tend to be quite harmless, even amusing in a surreal way. At a friend's birthday he spent a good amount of time lying flat on his back on the porch laughing happily, an empty plastic cup clutched in one hand. Just...laughing. All to himself. Had it not been for the overwhelming party atmosphere, it would have been almost serene.