Taijutsu, I love to see everyone's unique fighting style. Even the way they use a sword as that is also classified as Taijutsu.
After that Ninjutsu, theres some really awesome ones out there.
Last Genjutsu watching someone get owned in a second is boring they just fall to their knees and collapse. I know genjutsu's take great skill to use which is why I respect characters that are able to break out of them.