Geometry was SO HARD for me for whatever reason. I'm assuming because I had a really hard time visualizing changes/etc. Algebra, however, made perfect sense to me, and I actually enjoyed it. I still do, lol. Calculus might've been good if I hadn't been taking 22 credit hours that I also had to focus on... Who knows.
History wasn't easy for me in college because my memory was so bad (this is before I was dealing with seizures - at least as far as I know), but I was always really good at analyzing the overall picture, so I did well on my essays/final exam essays.