Arcanum
Eschelon
and many others lister here could go into the "Flawed but fantastic category".
Arcanum is a real treat if there any folks out there getting into the old style Fallout games, or if your a fan of disco Elysium.
I mean, it's really broken in a lot of places, but it has some of the most roundabout ways to solve quests. I once completed a run through as a pick pocket only, because ultimately your always trying to get through some kind of door, and someone has a key, or a letter, or McGuffin that you can get in order to move to your next objective.
You can defeat the final boss with words if you are Charismatic enough, intelligent enough, and have been following some of the lore and philosophy conversations in the game.
You can have a high Charisma and lead a team of like 6 bruisers to beat everyone down for you.
Wield outrageous magical power, or build a death bot and throw grenades at people while you blast them with your Elephant Gun.
A very rich character experience from the people who would go on to make Fallout New Vegas.