In my experience using tumbling services the best I have used so far is:
1. https://[banned mixer]/ - after bitmixer.io closes its services, I switched to them. And so far smooth and no issues at my end as I have been using it for almost half a year already. Highly recommended.
2. https://chipmixer.com/ - Fairly new in the market but very trusted and re-invent how mixing bitcoin are. They even claimed that they don't store historical logs of their clients.
Those 2 are fairly solid already. If ypu are not contented, then you might as well try Bitblender, although I can't comment on them because I haven't used their service yet.
What I'm only worried about bitblender is that many are trying to imitate this legit mixing service so I just have to warn those people out there that wants to try out their service. Look at the right website address of them and don't always do research because it can also happen to other legit mixing service.