I had played Red Alert at a friend's house and when I went to buy my own copy, the guy at the shop recommend I get Tiberian Sun instead, as it had just released. I must admit that I was a bit disappointed in the gameplay as compared to Red Alert, but the world building was amazing. I spent hours in the map editor building huge bases and custom units.
RAedit was such a fantastic tool. It was really frustrating how much more difficult it became to make custom maps once the games went 3D with Emperor: Battle for Dune and C&C: Renegade. I tried my best, but the learning curve for 3DSMax was steep.
It’s what gave us DotA, and Tower Defense, and maybe some others I’m not remembering - maybe even vampire survivors ish for horde survival?