Maximum Doom is a haven for trollism in maps, as it was released in '95 and was created primarily by a horde of douchey teens who've just discovered they can create their own Doom levels.
Off the top of my head, I can remember shit like -
pressing a button that does nothing but drop the ceiling down on top of you;
Keys in secrets;
Keys in secrets within secrets;
Making the most maze-y sections of the map invisible on the automap;
a red key door with a yellow frame, no red key (but there's a yellow key and no door), inside is the only weapon you don't get in the level;
Starting a level in a small square room, press the button and it drops down into a bigger room and you're surrounded by chaingunners;
Teleporters where the destination is the exact same teleporter pad;
The ol' "item in an inescapable lava pit" trap;
The "infinite staircase" (small hallway with stairs and teleporters at either end, you're trapped in there forever if you take the wrong one elsewhere in the level);
the one where there's a picture of a cyberdemon on a wall to psyche you out, then when you walk up to it, you get teleported in front of a real one;
Basically all of DARKGAT2.wad
So yeah, go and like, play it