I've actually only been to a few hosted by other people, as I am usually doing my own Halloween party thing (guaranteed to be good! :)
Probably my worst was because I drank too much lemonade that had been "flavored" with vodka, and I got so drop dead drunk that I spent the night cuddling the commode. :p I had dyed my hair bright orange/red with a thick gooey Manic Panic sort of hair dye, (and how that enhanced my witch costume has totally fled my memory banks...) and let me tell you- that dye did not come off the seat for months! (pained snicker)
I always feel sad when I go to a purported Halloween party and no one wears a costume. What's the point? May as well call it a Labor Day party then! :)
Minx (sober)