First aid kit. Always a first aid kit (though to be fair, I never leave the house without one, let alone travel to another city).
Something as simple as band-aids and some purell is usually enough, but I like to go God-mode on mine:
band-aids, tensor bandage (at least one), painkillers, pepto (or equivalent), saline flush (for cleaning larger cuts/scrapes), alcohol swabs, purell, gauze, medical tape, cotton swabs, pen, pen-light, and cold meds (no one likes a cold at a con). Of course, this varies depending on what I've got on hand, but that's a pretty average kit for me.

Otherwise, the only things you didn't cover are snacks, and music for the car.

Agree with the first aid kit for sure, also emergency sewing kit would be good. As for the Alcohol one convention we had all of ours out (this was Katsucon at the Omni in DC) and secruity confiscated it all and wouldn't return it to us at any point during the con, it pretty much ruined things. SO that being said, just be careful of it and if security comes to your room be sure that the bar isn't in plain sight.

>>5115371

We usually carry the boxes right through the front lobby and have never been stopped. Everyone in our room is usually of age, and I've never heard of anyone's liquor being confiscated before. Must of been a pretty prude hotel...

>>5115385
It was, it was terrible. They didn't see it in the lobby because it was packed away but we put all the bottles out on the windowsill of the room and they took it all when security came up to fix our lock. Needless today we tried to do something about it but were pretty much laughed at which INFURIATED me. So we never went back and try and trash their rep whenever possible. We should have called the cops or refused to give it to them or just left to go to another hotel. But anyway, I caution people of it because we were of age, we owned it all , we weren't flaunting it around the con, it was all in our room and they still took it all. I just don't want it to happen to anyone else.

I bring my laptop and my external harddrive to cons, so that when I inevitably fail to bring a girl back to my room for the night, I can at least fap and weep in solitude and get my beauty rest.

I always bring a pack of cards to play drinking games at cons.

The essential convention item I always bring with me is my camera and camcorder. Even in times where I commute to cons, it's still an essential item. That way the memories of the con will always stay with you forever.