I really liked the Role Playing maps honestly, as cheesy as they were. For those not familiar, you didn't real have a "goal", you just kinda messed around and told a story. Kinda like ehhh... It's a horrible comparison, but Dungeons and Dragons without the stats.
I remember I had a game where I played a Bandit that went on for hours, as well as a time when I was a Pilot.
The Resident Evil/Night of the Living Dead maps were fun as well, especially later on when they got more complex. When these maps started it was literally just 8 (its 8 right?) people that just kinda stood around while their marines shot zombies. It was still fun though, you had to get to the right place to stand, and since there was little game-action involved, you could talk to people and meet some really interesting characters. Later on the maps got more complex, and you would have different weapons that you could pickup/drop, you had to keep an eye on your ammo (and press "r" to reload), and you could set traps. There was a level up system and boss fights as well as mission objectives. It was crazy.
If you could find decent people, Life of a Peasant provided some interesting entertainment as well.
The actual game of Warcraft 3/Warcraft 3 The Frozen Throne is very good, and it's strange that people are in some cases more familiar with DOTA than the game itself.