For me it’s first person puzzle games. I can think of maybe a dozen off the top of my head that came out in the last decade. I especially enjoy when they’re open world. The ability to just quit a puzzle that’s stumped you and go try something else for a little bit is incredibly refreshing.
Although they’re somewhat different the modern Hitman trilogy scratches this same itch for me (especially turning some of the guidance in the UI off and exploring the levels yourself, they’re actually designed well for that). Gloomwood is in early access but is shaping up really well and is inspired by classic Thief.