Man, so many choices...escort quests tend to be low-hanging fruit, but honestly, if the character follows YOU rather than plodding forward on a predetermined track, they're tolerable. Some of WoW's quests were irritating due to the copious backtracking or crappy quest item drop rates; one of the worst in that regard was "The Green Hills of Stranglethorn" from the pre-Cata days.
But to me the worst sidequests are the puzzle ones where knowing the solution isn't enough, you also have to have some sort of inane, pointless talent to get through it. Best example I know of is in The Secret World. There's one puzzle where you have to decode a message in morse code. Realizing that's what needs to be done isn't enough, you have to be skilled at writing down morse for translation. The problem is that God damn message is blitzed by you incredibly fast, and there's no option to slow it down. Worse yet, the way the beeps come through, the appreciable difference between dots and dashes is vague at best. If a dot takes half a second, a dash takes 3/4 of a second at most. Telling where a given letter or number ends and the next one begins is well nigh impossible. It certainly gives you an appreciation for the attention to detail and skill at comprehension of the old telegraph operators, as well as people in the military who still use it. But really, outside of those two user groups, who else is likely to be skilled in this sort of thing? Boy Scouts, maybe?
One caveat to this is that I don't count puzzles in sidequests that take some figuring out. Stuff like sliding block puzzles, peg-jumping puzzles, riddles, that kind of stuff, while it can be tough and sometimes frustrating, I don't consider a sign of poor quality because they're tests of things like reasoning, knowledge and deductive thinking; mental skills that anyone should possess to at least SOME degree. It's not asking you to have some unlikely knack, such as being able to understand morse code like an expert telegrapher, be able to identify obscure bird species by the sound of their calls or play a musical score by memory after listening to it by tapping corresponding letter keys on the keyboard for the notes (i.e. tap a for an a note, c for a c note, etc.)
