Even the sports franchises started out nobly. =)
The first few years of NHL and Madden titles for the Sega Genesis were revolutionary. They were the first games in their genres to somewhat accurately simulate their sports in a fast and fluid way.
Madden in particular was something like a tour-de-force of software engineering: a full 22 independent dudes characters on the field, actually playing their positions, following a realistic and deep playbook, nearly all of American football's arcane rules represented, and a nifty pseudo-3D playfield.
All written in assembly, on a 7mhz CPU. Mindblowing.
The first 3-4 years of annual updates were incredible. They were iterative, in the best possible software engineering sense of the word. Core ideas refined and polished, a few new key ideas added onto a strong base design.
Madden '93 (the third installment) is where it peaked for me; some say Madden '94.
https://www.youtube.com/watch?v=wm9fXnBF67g