Now that I recall some things about Zero 4 I remember it being my favorite in the series. I remember it having the most polished game mechanics and level design mostly, and the best music too. I haven't played it in a while though so a lot of stuff about it doesn't stick in my head that well.
Man the only thing I don't like about these remasters is that they always insist on doing really noodly solo sections that aren't in the original song. I'd like it if it just looped normally like the originals do.