Rounds rarely happen with my group of friends. We all drink vastly differently and frankly, I don't think any of us trusts each other to not screw the other at some point. So it effectively turns into getting our own drinks, or at best a 2 person round if it's particularly busy.
Anyway, something that pisses me off during every shift at work, price matching trade ins. It's just a pain in the arse. Worse thing of all is if someone brings in a huge stack of stuff and asks you to pricematch it. It takes forever, you can easily get confused and if you do you have to start again, every price being matched has to be verified by a senior staff member (who has to enter their till number for each price match) which serves only to piss off them because they have to be dragged from what they're doing. Or the other way to do it, which you're not supposed to but makes thing easier all round, is to get a senior staff member to sign into the till and just do it all under their till number, in which case come the end of the day you print off your sales reports to prove you've done the work and hit your targets, and they're wrong, because the trade in wasn't attributed to you.
I find it annoys me just that little bit more when you know that people just walk in and say 'Can you price match _____ mate' when you know they've not got a clue what the place they've asked you to match would offer in the first place, they just assume it offers a better price.
The plus side of all this is the little glee I get on the rare occasions that the price match actually reduces what they'd have got on an item.