Most of the sites I used are gone. I still have a lot of stuff for TS2, but I don't know what most of it is, what with the long non-sensical file names some of it has. Mod the Sims is of course a go-to for any CC.
You might have to search because some are over on tumblr and other sites. I know I got quite a lot of my cc from Cradle of Darkness site, which is still going strong. Others such as NewSeas and CoolSims (CAS assets) etc. put a lot of their stuff over on MTS. I know the most of my cc I have right now was downloaded within the last five years rather than sixteen years ago. It's still out there and plenty of it. I have a lot of stuff also from the sites listed by others.
"Games Are Not The Place To Tell Stories, Games Are Meant To Let People Tell Their Own Stories"...Will Wright.
Glad to see that Parsimonious is still with us! That was a happy and fruitful hunting ground for me way back when. Definitely a place to go for CC of other eras and cultures than now. Lots of it, and very well done.
Comments
http://affinitysims.com/index.php - they have stuff for TS2/3/4
Lee-fish - Forum with several creators, not looked around what they have
http://www.parsimonious.org/sims2.html - Parsimonious is a good ol' creator from TS1 also. You'll find stuff for all iterations.
http://sims2.aroundthesims3.com/ - Around the Sims has been one of my favs since TS1
For a bigger list of CC sites, Pleasant Sims
Gallery: Kathykins
AHQ - Game help and Bugs