The open world concepts for each level.
The story is found and told through other characters. A lot of the story is shown rather than told.
Thief 3 has the most horrific level design ever in the orphanage. A game review had a review (really more of a worship piece) just on that one level. (I think this is the review: https://www.pcgamer.com/journeying-into-the-cradle-in-thief-deadly-shadows/)
The stealth mechanics actually require stealth and are multivariate. Most stealth games stealth systems now are actually less advanced.
They’re great games.
God I remember having to actually disable enemy AI to get through The Cradle as a kid.
Thief 1 and 2 have incredible community made mods that completely overhaul the graphics and make it quite a beautiful game. Said community is still alive and well over on the TTLG forums, making fan missions for the game to this day (including the highly regarded Black Parade, which is basically an entire game made in the dark engine).
The only stealth games I’ve played that come anywhere close are Dishonored 1 and 2 (which, unsurprisingly, had a lot of Looking Glass veterans working on them).
