I have to say spiders, cockroaches and heights. Sadly, my sisters hate spiders too and they make me catch it every time one gets into the house. It was really horrible when I have to catch one that was big as my thumb. Not to mention, it was jumping in the cup I used to catch it. *shivers* Just thinking about it still freaks me out.
Cockroaches are dirty, fast, and can fly. I used to live in Thailand and the cockroaches were EVERYWHERE. They were running so fast I had to jump on a table and try to keep my eyes on it.(Making sure it doesn't run up my legs. I had a friend who caught a cockroach going up her pants.) Unlike the American cockroaches, these little aliens can fly and might land on your head. Onetime, a cockroach was found in my sister's bedroom and it was flying everywhere. My sister was screaming her head off while I ran out the room, trying to put the distance between me and that thing as much as possible.
For heights, it depends how high it is and if it has rails to hold on. The old building I used to live in had stairs with no rails and if you were to look down from the stairs. it goes down pretty deep. Just looking at it makes you feel like something is pulling you down. I had to walk right in the center of the stairs every time I use it. Forgot to mention that the building had 8 floors.