Halo 2 for me, if you're meaning played with any dedication. Rust is what I'm fighting on my decorative iron for my front porch.
It's minecraft mixed with dayz and a little CoD. Not sure how that is nerdy compared to something like Titanfall or a long list of RPGs or mmorpgs.
Is rust that stupid ass "survival" game where everyone is just a **** and shoots you in the face? That game was actually built as a tracker for future orange jumpsuit sales.
I don't play minecraft but I see people of all background and ages playing it - has a lot to do with how many different platforms it's available to.
It was built by Garry from Garry's mod. Some people play it like that. Just depends if you decide to play on the server of 15 year olds or not. Different servers have different rulesets - some only focus on base building and community, some hardcore pvp, griefing and raiding and a mix in between those two extremes.