I often get annoyed by them not enforcing priority boarding. Either the bar is so low that 75% of the aircraft have priority or the line contains many who are not entitled to priority.
A particular problem in CE though is the blocked front lockers and crew baggage at the front meaning that even when boarding early and seated in 1A your bag is above row 3. This is then a hassle after arrival when the aisle is jammed with impatient souls wanting a quick exit.