Hmm, i probably prefer shorter or medium length series anime. I like how there tends to be a greater emphesis on telling the story and establishing the characters than in the true episode crunchers like bleach and naruto. But really, series length isn't that much of an issue to me, as long as i'm enjoying the plot and it isn't dragging from unneccesary filler i'll watch just about anything.

I think that's what put me off bleach actually, the near constant filler was irritating enough but even when you did get to the main plot it was just a monotomous sequence of fights completely removed from any narrative. grr...