HARP/Rolemaster
Looking over my buddy's collection of these books I'd like to run a small, quick adventure with the system to see how it all goes. Thinking 4-5 members, levels 1-4 with a quick premise: save a city in the path of some horror or another, clear out a dungeon, or something like that. The creation process seems somewhat involved, but once the characters are made it seems like it shouldn't be that hard.