I’m very happy with RoboSats tbh, it’s super easy to either publish your own buy offer or take someone else’s sell offer. I have mixed experience with the liquidity though. Some days there are a lot of cheap sell offers and some days there is almost none. Sell offers are usually at a ~4% premium to “current market price” in my experience. The traffic is over TOR, your “account” is just a pair of PGP keys, the chat between you and the seller is end to end encrypted and you can choose between receiving the sats on-chain or over LN. Robosats is also open-source and the code can be found on Github.

Bisq usually has somewhat good liquidity and supports a lot of different payment options but the UX isn’t too good and from my experience, the premium is a bit higher than on RoboSats. They are working on Bisq v2 which is supposed to have a much better UX so I’m hoping they succeed with that. Bisq is also open-source I believe and can also be found on Github.

Relai offers the option to buy bitcoin without them KYC’ing you but a bank transfer is the only option for buy sats from them which could take 1-2 business days to go through. They just added VISA payments but you have to KYC with them and VISA also takes a fee, so it’s faster payments with VISA but it’s more expensive. They are a company in Switzerland and are therefore working under Swiss laws and probably has some data stored about you for legal reasons.

I have tried Peach once but there isn’t very good liquidity for now which makes it hard to find offers when you want to buy more sats. It’s pretty new though and they’re in a public alpha/beta testing period so I’d give them some time. I believe Peach also operates under Swiss laws so you don’t have to KYC to use their app but I’m not sure if they store anything else about you.