I think this easily has to go to Warhammer Fantasy Roleplay 2nd Edition or WFRP2 for short.
One of the things I really enjoyed about WFRP2 is how brutal and unforgiving it is. Unlike my typical D&D games, I felt a lot more vulnerable and in danger, like my choices really mattered and could make the difference between life and death. The careers system instead of the more abstract ‘levels’ really made my character real a lot more real, like they had a real past and a real future to aspire to, rather than just getting ever more powerful.
I remember starting a game as a lowly thug called Albrecht. Eventually, after many misadventures, he climbed the career ladder, serving time as a torturer, interrogator, barber surgeon, physician and almost became a noble after founding his own town with a bunch of ill-gotten gains stolen from Chaos Dwarfs.
We stopped playing for one reason or another – drop outs of players and/or GMs and we’ve never returned to playing in that world or using that system which is a shame.