Real answer:
Planescape: Torment was pitched as 'the entire game is the character generator.' It's also
narratively forgiving.
That's a bit of a exaggeration, however.
Elder Scrolls (
Daggerfall, Morrowind, Oblivion, Skyrim) games offer some very impactful character development loops.
Gothic games and their descendants (
Risen,
Drova) have an interesting power/character curve. You technically can't build in a wrong direction, but you can definitely be unprepared.
Final Fantasy Tactics games (and
Front Mission 3/4) offer lots of particularity with how you develop your team. They are also relatively easy.
Fallout games generally have interesting character development mechanics. One, Two, and Tactics (in particular) are very table-toppy and can offer some real nuance in builds. I'll also offer
Arcanum as an interesting CRPG with an equally interesting character-ing.
Underrail lives in that same universe, but can be pretty crushing if you don't guide ahead.
Wasteland 2 and
3 are also relevant here.
The Owlcat
Pathfinder games can offer some pretty intertwined character play. It basically runs on DnD 3.5 (reborn as Pathfinder), which offers a hell of a lot of powergaming edge.
Shadowrun Returns, while a definite rules reduction on the original tabletop, can offer some interesting character play.
The original
Baldur's Gate (One and Two through to Bhaal) games are a very slow, methodical character
expression experience. They don't offer many options, but many things you do will whip around at some point. Infinity Engine throwback titles (
Pillars of Eternity, Torment: Tides of Numenera) are both very in-depth meditations on character roleplaying. If you want to have almost no control over your character, you could try
Disco Elysium.
System Shock 2 is a personal benchmark for mixing mechanical gameplay expression with a character sheet. Prey (2017) is its distant spiritual successor. Deus Ex lands in this particular quadrant as well.
Alpha Protocol was a very lofty concept of a game that delivered on a lot of what it promised, but left a lot on the table. It's a very curious choose-your-own adventure with extras.
I mean, I could go on.
Hehe, I HAVE been considering this. It's the only game I can think of with huge variety and some flexability. I keep going melee ranger though.
Path of Exile, when I played it over a decade ago, was a like all the worst parts of Diablo-like action RPGs isolated, amplified, and recombined into an
absolute fruitcake of a game. Try it, definitely.