STL-OGG was a great route and one of the last nice trips I took as a non-rev. Flying DCA-STL on 757s was always a nice treat, especially compared to the jungle jets that now appear on that route. Some of my other faves included:

STL-HDN
STL-JFK on 747s (#844?)
STL-LGA on L1011s (big fan of #300)