Boring.
There's something viscerally exciting about a reciprocating engine - the sound, the smell, the vibration, the brutishness of it.
I once got a ride in a P-51. There's just something indescribable about that V12 Merlin catching, and then digging in when the throttle is opened wide.
There's a reason for the title of this book: "Sigh for a Merlin".
Yeah, though I wasn't so lucky, I also love the sound and smell of a combustion engine. But I think that's generational, not something inherently more exiting. But I guess I'll have to wait and see what my grandchildren have to say.
As for generational, I've always been sorry that steam locomotives went off the rails before I was born. Diesel electric locomotives are boring.
Because you can now hear the tyres, you can hear how good the driver is.