Most math's, due to the fact that I always get crappy teachers.
Most sports, due to the fact that I'm not all that aggressive.
Singing, even though I used to be an amazing singer, my voice changed and I just can't sing the same anymore

I'm bad at drawing people or animals unless I have a picture in my mind or something to copy.
Vibrato, doodles, and shifting (on the viola). Vibrato is when you make the note sound like shake sort of. I can sort of do it. Doodles are when you have to do a certain fingering and do a certain amount in a certain bowing. And shifting is when you move up the string to hit a higher note. I normally can't do it quick enough. Haha, ungh.
Haha, I'm bad at quite a lot.