Sims 1 Superstar has a killer soundtrack. Especially its Studio Town Build Mode music.
https://youtu.be/83uj-dQ3NSo?list=PLCDAA0D2C87F95DF2
(to be fair, I heard one of its tracks through Spore first, it's called Pump-U-Up and I was very delighted to hear it originated from a Sims game)
https://youtu.be/FjIOCIC1noA?list=PLCDAA0D2C87F95DF2
For Sims 3, whatever pack gave me this piece:
https://youtu.be/zH3hspjc66o
As for Sims 4, the one I'm the most familiar with, it's hard to say because there's a lot there I like, but Dine Out has my favorite CAS music
https://youtu.be/CxPVi8CovMM
