I missed the old Glukkon foot music. That music is so much better than the new foot music.
I also liked the dark nature of AO and AE and I think the level in MO that captured the old game the best is Magog Motors.
I also missed cooperative Gamespeak with enimies. Yes, insults were fun, but in the next game I think you should be able to switch back and forth between insulting and cooperative Gamespeak.