I think Age of Empires 2 will always be in my top 10 list of favorite games. It's in a similar vein of just upgrading graphics, but I also really enjoyed the spin-offs built on the same game engine: Star Wars Galactic Battlegrounds and Age of Mythology.
It's especially exciting that it's more popular now than it's ever been. With the 2019 re-release, it's pretty consistently been around #50 in top active players on Steam at any given time. And they keep updating it still. It's been a blast to get back into it and try to actually get decent at it. And the pro scene keeps getting bigger and bigger tournaments too.
