I have a fondness for what I describe as "Hardcore Military Vehicle Sims." Games which attempt to replicate the feeling of controlling a death machine to an accurate degree. I like the feeling of piloting incredibly dangerous vehicles I know I'll never be able to use in real life.
One such example that always comes to mind is
Jane's Fighters Anthology. The game eschews
Top Gun-esque dogfights in favor of a realistic combat model, where you rely on your instruments and fights are over before you've ever had a chance to see the other guy. In addition, the game casts aside gamey abstractions like health, and instead simulates hardware failures of your craft that make it more difficult for you to continue flight, only "killing" your plane in extreme damage situations.
It's a shame they don't really make these kinds of games anymore. I'd love to see a game like this with more modern graphics. I know
Ace Combat exists, but those games are more "arcadey" than "simulation," falling squarely into the aforementioned
Top Gun-style dogfights where your plane can inexplicably carry a hundred missiles, but only five flares.