Ah yes the good old days when there were more benefits to staying onsite than you could shake a stick at. ERT on Air and Nemesis, priority passes for 4 other rides, discounts on certain games and merch, priority seating at shows (when the park actually had shows), kids activity packs in the rooms.
Here is the front of the priority passes given to hotel guests in 2003. At that time it was Black Hole (which was a winner because that queue was a killer, although you did get to listen to German MTV with the swears still left in, wunderbar), RMT, Duel and Corkscrew.