Today's nominee: the crew at a major hub during the morning arrival push (translation: plenty of jets sitting in the penalty box waiting for a gate to open), who literally cut in front of us as we were approaching our gate and stole it. Just pulled in front of us and darted into the gate. We'd already been waiting for that gate for half an hour.
The crew didn't call the ramp tower for clearance, as specifically required for that gate, and entered the ramp without talking to anyone... They ignored multiple transmissions from the ramp controller ('Stop, stop, stop!! That's not your gate!!')
Result: a tremendous cluster on the taxiway. We had to taxi back out of the ramp and back to the ol' penalty box for another 30-minute wait. The hour delay caused at least a few misconnects among our pax, all because one crew couldn't be bothered to read their 10-7 or double check their gate.
Thanks gents... 🙄