Myself and a few other guys worked out how to get BF1942 bots to fly helos and throw grenades, which they couldn't do at all before we lit up their code.
I had kraut bots manning the stationary MG42s on the Omaha Beach map -- you couldn't even get out of the LCVP on the first try without getting waxed by MG42 fire.
The El Alamein map, with 64 players, you could put two humans into it and not know which of the 64 were the 2 humans. Tanks, APCs, fighters, bombers, the bots would use it all.
A friend of mine and I were playing Co-op, and he kept yelling at me because I wasn't flying the dive-bomber he was in to the target he wanted us to hit. I busted up laughing, and he got mad, until I told him, "Dude, *I'm not the one flying the plane you're in."*
Bethesda worked out the value of mods. People are still playing -- and, here's the bottom line butter, still *buying* -- Fallout 3 and Fallout New Vegas 15 years after they were released.