Plugged cigars or cracking in the middle. If a cigar is cracked at the head or the foot, you can kind of fix it, but if it is down the middle, man that is a pain.
Plugged cigars and people who think but do not really know how to light a cigar.
Take your time when lighting as you would when smoking.
My current pet peeve is the lack of free space in my humidor. I know that should be a good thing, but I keep getting new sticks with no where to put them. Guess it's time for an upgrade. Also, I can't stand it when people ash every few seconds like it's a cigarette. Let it burn, let a good ash build. People try to rub it against the ashtray to keep the ash off and then wonder why they are having burn issues.
I just hate an uneven burn, drives me nuts...I don't wanna have to think about "workin" the cigar, I just wanna light up, and enjoy it...uneven burns and re-lights are the bane of cigar smoking in my book.