WC in the general series were all great, but the first game (edit, first space sim I played I mean) where you had to grind that I ever played was Privateer and that was the greatest for a 12 year old.
https://en.wikipedia.org/wiki/Wing_Commander:_Privateer
Later on, I really enjoyed Freelancer but by then I was older and it didn't have the same effect on me. https://en.wikipedia.org/wiki/Freelancer_(video_game)