Favorite dead game modes?

Iv been playing this game over a decade and was talking to an Irl friend who got into this game with me back in Garry'smod 9. We were discussing our favorite game modes that has sense past or have only One server online. For me this was a fun yet sad game but over all I think I had more fun in the end. I figured Id ask this question here to see what gems I might have forgotten.

Also my top three picks (So I leave some room for the rest of ya )

Winter Survival

Sassilization (The Little RTS game that had the lobby)

GangwarsRP (Even though it was Chaos and maybe even ground zero for a new generation of Toxic that flooded Garry'smod....)

Personally can't wait to see what some others write!