Zoo Tycoon 2
Just after Minecraft, the second reason to create a website was Zoo Tycoon 2.
I play this game for more than ten years. In fact this game is awesome because we can do what we want. It's also very easy to mod (to add extra content to the game - create entities).
In reality I don't usually build zoos on Zoo Tycoon 2. I use it to build various sorts of buildings like cities, military bases, buildings with special architecture, etc. I also make investigation/action videos on YT (and help some people to make theirs). That's what we call "machinimas" that's to say movies/series whose the film sets are in a video game instead of in real life.
I also make a lot of mods for the game. You can download a lot of them from this website.
You can find them in the dedicated page of this website.