MM6 had some big ones, too. The final one with all the Cuisinarts (Tomb of Varn?) was a gauntlet-and-a-half. For that matter MM7 had a fairly long one as well with the tunnel to Nighon. Ascension Peak in Wiz8 wasn't a complex map at all, but it was a pretty tough slog.
Don't think the tomb had any cuisinarts in it, as it was mostly genies and defenders of varn there (dogfaced guards). Huge dungeon though, far too big for my taste.
All in all, MM6 and 7 have some of the best dungeons around. Some are too big (the tomb, the castle in the undead city, etc), but most are excellent.