OP, you will have lot of work as actual list of such websites is long. My memory is really bad and I'm a bit lazy to Google on my phone, so, I can't you help much with updating list. Now I only can remember Bitmixer.io (if I'm not wrong), one of first big Bitcoin mixers. They shutdown for voluntary reasons officially.
And damn, BTC-e was seized in 2017 - that's already 8 years. Time flies so fast. Still remember having account there.