I'm sure it's different for each man. If you're trying to attract a certain somebody, see if you can find out what kind of hair turns him on.
Personally, long curly hair cut below shoulder length (just above bust level) worn down drives me wild.
Long hair, regardless of form (wavy, curly, straight, etc.) is hard to keep, but it's rewarding because I think a lot of guys would go for it!
As for hair accessories, they generally have no effect on me, (again, it depends on the guy), except that I think for casual special occasions, a flower in voluminous hair is cute (not so good with short hair).
depends on the girls hair really, down is nice...when a girl has curly hair and she puts it up in a bun I don't know why but I think its so sexy. it makes her look like she's going to teach me a lesson or something haha.