I hated rugby. When you're small and not fast but can kick the thing, being banned from kicking (for a year) just because the teacher decided it would help us learn took me from being able to protect myself and use skill to being pummelled.
I liked cubs, but hated scouts, mainly because scouts was a form of indoor rugby that was what I imagine football in the middle ages to be (the only rule seemed to have been "thou shalt not pass").
Cross country was fine, and it was amusing to beat the kids who were more talented purely on the basis of being able to push myself harder. I guess that attitude explains why I like riding my bike up hills!
The main thing I disliked was writing essays. Not too long, not too short, gotta have the right structure, and when by a quirk of fate I was able to submit the same English essay to 2 different teachers I got completely different marks. If one person can grade something 15/20, and one 7/20 , what's the point in trying? Oh yeah, and history. 3 years spent learning about everything that happened in britain before 1500 and then I got to drop it. That was useful - really helps put into context modern issues like slavery, empire, industrial revolution, and various historically based political issues.