OpenTTD.
OpenTTD.
I wanted something slim and light, so I got the Waterfield Magnetic Case (in all waxed canvas). Keep my Steam Deck in there any time I'm not using it.
I've played it for many years on a desktop computer with a mouse, but now play it directly on the Deck for the pick-up-and-play convenience. Controls took some getting used to, but it looks and plays very nicely.
OpenTTD.