1. Large groups that run you over (and usually nobody even says pardon me).
2. Tour groups that congregate at bottleneck places (i.e. the bottom of the UP escalator/stairs downstairs in the Land, so everyone getting off Soarin and trying to go back upstairs is blocked).
3. People with strollers the size of small cars who park them in aisles instead of pulling them to the side, so nobody can get past. For that matter, people who take giant strollers inside the small stores - park the darn thing outside and carry your kid, those little stores are not made for dozens of doublewide strollers to be inside.
4. Line cutting at rides. This didn't used to happen, but now it happens ALL the time. Entire parties (usually younger people, although we had one older couple climb the ropes outside Pirates, too), and they basically dare you to say anything to them.
5. Since FP+ went into effect and everyone's forced to do more Standby, the new "runner" is the guy who goes to hold a place in the Standby line, while the rest of his party is elsewhere, and then all 12 of them climb over the ropes and through the crowds to get to him.
6. Getting run over by strollers and scooters (often on purpose, esp the
scooter people - they seem to think they have right of way anytime, anywhere). I stopped wearing anything other than tennis shoes with closed heels and toes because stroller and scooter people do not look where they are going, and run up on you - I've been bloodied by people more than once, and they just do not care what they've done.
7. The sheer number of people on scooters who are not disabled or elderly is nothing short of... well, get an exercise program going, so you can walk. You'll feel better, trust me.
8. Disney not doing enough to eject day guests when hard ticketed events start. Yeah, Disney checks bands to keep them out of the shops and stores, but they all camp the sidewalks and center castle court for free parade and fireworks shows.
9. Disney deciding it was OK to cram 3 adults into Doombuggies. Yes, this happened to us. 2 guys over 6 feet tall and me (I'm 5'9"). This did not work well. We were draped in each others laps and had shoulders and legs hanging out both sides of the car. (We are not pooh sized, but my 6+ foot tall guys are far too wide-shouldered to be crammed into a buggy with a third adult. This should never be done unless 1 of the 3 people is a child.)
10. MyMagic+.
11. Hotel rates on property being 2x to 6x what they should be for the star quality of the room and resort.
12. People videotaping (with bright light) and taking flash pictures in the dark rides.