Area that was biggest waste?

You got a perm badge for killing the boss which back then was a big deal since you couldn't get perm badges outside of events. Other than that though it's kind of "meh"

Ghost Ship Exorcist badge is perm, has 3rd tier potential, and was around before Colossus.

Most of the theme dungeons below level 100 seem pointless to me. Chryse in particular was my least favorite. All I ever did there was solo Xerxes repeatedly for exp.