Favorite Enemy Closet

[Maser]

As the title says, what's your favorite enemy closet to run into?  For me it's a Cacodemon closet because even though Pain Elementals are my favorite enemy, an entire closet full of Cacodemons all smiling at you at once always puts a smile on my face as well! 

[𝙳𝚊𝚛𝚔𝚗𝚎𝚜𝚜]

Imp..

[Pierrot]

Cyberdemon right in front of you. Sometimes such a jump scare is just hilarious.

[Pegg]

Cyberdemon so I can watch him while he sleeps.

[Dark Pulse]

Any demon that you see just long enough to recognize it's there before it steps on a teleporter tripwire and fizzles off elsewhere... leaving you with the unknown until you hear it getting closer to you.

[TwinBeast]

The one in E1M3, pick up the key, the lights turn off and the imps come out. Other similar traps are cool too that have something else happening simultaneously.