I don't smoke or drink, and it bugs the hell out of me when one of my bandmates (it's usually a singer) puts an ash tray and a beer on top of my amp.
It bugs me when people don't understand when they ask if I'm a bass player and I say "No, I'm a musician".
It doesn't at all bother me when another bass player wants to use my rig at a show, but it DOES bother me when they don't bring their own, just EXPECTING to use mine. Even if I was SURE that I could use someone else's rig, I'd bring something of my own if for no other reason than just to show that I was prepared in case they said no. I've actually been to shows where the bass players in both the opener and the headliner left their amps at home because they thought the other player was bringing a rig! haha
A band I was in several years back used to host an open mic jam night every Tuesday. No big deal if people use my rig for this purpose, but I used to hate the people who came to these without a bass and wanted to use mine. If it was someone I knew and trusted, no big deal. But there were kids who JUST started playing and knew nothin about nothin and I didn't want them using my basses.
It bugs me to death when a singer tells unfunny jokes or otherwise makes an ass of himself between songs at a gig. It's embarrassing.
It bugs me when I show up to practice only to find out that the drummer isn't coming. Why the hell can't people use a telephone?
It's annoying that every time I walk into a music store to check out an amp, every one of them has the EQ set with bass all the way up, everything else all the way down. I evaluate every amp by how it sounds flat. Any amp I have to adjust the EQ on is not for me. It bugs me any time a bass player thinks the only thing worth hearing on an amp is how loud it can go or how much sub bass it will put out. When I was younger, I was guilty of this at times, but now it bugs the hell out of me!
Lastly and most importantly, it annoys me to no end that I'm apparently not smart enough to figure out how to get a good sound with a compressor! Either it ends up sounding great for slap and like a turd for everything else, or it sounds great for fingerstyle and terrible for slap, or it ends up sounding awful for everything! Someone help! haha
Jake