1. Female domination. I like the idea of a girl taking charge and showing her lover (be they male or another female) what's what.
2. Menage-a-tois. The more, the merrier and all that. I especially like female-female-female and male-female-male threeways, but really, any threeway is a good threeway.
3. Tickling, in conjuction with bondage or not. Whether it's just playful tickling or outright tickle torture... I'm a sick freak and it gets me hot.
4. Role-reversal. I like the idea of someone who's not usually in control of the relationship topping (but not raping) someone who usually is, especially if the person who usually is in control is just a leeeetle too cocky about it.
5. Crossdressing. I go back and forth between trying to decide if a boy dressed like a girl or a girl dressed like a boy is hotter.
I generally prefer het and femmeslash, but honestly, slash is good too and if the participants are hot enough, I'll go for anything.