Sims 1 - as a big pro, it was my first sims game and i enjoyed it as hell. Hot date was a great ep too. The biggest con imo is the sims not aging.
Sims 2 - the details is my big pro. Also, the wants and fears. Personality measured with points is a con imo.
Sims 3 - First time that we had traits (huge amount), sliders for almost everything, open world, expansions with tons of content, a lot of stuff to do... my pros would never end :) as a con, there's the need of a great pc to make it work without lagging.
Sims 4 - the pros imo are the gallery, much easier build mode, runs fast, pets are great... As cons, sims don't have distint personalities, most packs bring few content, whims were never updated...