Been too long since playing TS1 to coment, thought I do remember playing for hours at a time with no problem at all doing so. I also remember there being lots of cool features (hot dog carts, fish feeding ponds, sail boats in ponds, the wandering musicians, etc.) that have not seen since. The only con I can think of is retroactive, the camera limitations.
TS2: Pros: would take a book to list, though the greath depth of sim characters, intense and often unpredictable gameplay really stand out, especially in comparison to now. Cons: I know there are some, but need to think about it, after all it's made by fallable humans. I simply enjoy the game so much I tend to not notice/forgive any shortcomings. As for the graphics, remember this was ages ago so they need to be judged on how they were for their time. Can't look at 2005 graphics from a 2019 perspective, and same goes for sim structure and clothing.
TS3: I remember it as ugly, not relating to my play style, and almost impossible to get into. Bailed quickly and did TS2 exclusively.
TS4: Pros: Graphics are great, CAS is fun though face selection sorely limited in comparison to TS2, some aspects of build mode are actually improvements (move house/room, basements). Cons: as listed above and the tons more I expect will arrive in due course. Takes too long to list 5 years worth of bugs, failures, omissions, and all the rest of it.
A note on TS2 building, you must plan ahead, at least for the basics of size, layout, placement on lot and such. There are many more tools to work with and the results can be astounding even without CC. If I can build Titanic, you guys can build great houses, shops, and parks.