Killing floor 2. It's a great game, and I love it, but it has downgraded in every way since mid-early access. It's too bright now, they ruined the flashlight system, made it way too easy, and added some really stupid, annoying enemy types.
That said, I just can't get enough of it. After all the bad decisions they made, the core experience is so good that it's still a solid 8.5/10 for me.
If you're handy or willing to learn, it's entirely possible to ship of Theseus most pre-2005 vehicles. For some models it could ultimately be economical.