I have played games with couple shots of vodka and whiskey. I was soooo wasted that I laughed over little things and I couldn't even play the game cause I'm laughing so hard over that one thing. Probably the best moment of my life... Of course then comes the hangovers.
I've played America's Army Online drunk. I used to be in a clan with some of my American friends and yeah I was often drunk while playing. I found it helped with the lag.
Unfortunately, I've played games drunk, many times. I've played COD online a few times while drunk, and it wasn't too bad actually. I sent a couple of messages to the person who kept killing me as I was dying so many times, but other than that, I was OK. I was thankful I didn't think of putting my headset on.
Although, I've played games on my PC while drunk, especially the older medal of honor and call of duty games. I've been kicked from servers a few times because of how annoying I was getting. Usually though, the server admins can have a laugh with me, which is good.
I've played a few games "under the influence" before, but they were just to screw around on. Games like Grand Theft Auto or Left 4 Dead. If I played online it was pretty funny, especially during the GTA races in GTA4 xD
I played Fifa 14 online once when I was intoxicated, sadly putting my headset on is a natural instinct of mine and I was banned for a month for aggressive behaviour.