I have been using Bisq, Peach Bitcoin and Robosats.

The most developed is obviously Bisq and I like it very much. If you want to buy or sell on-chain BTC using SEPA, Zelle, Tranferwise, Revolut , Bisq is the place to go.

Robosats is good too because it supports Lightning. Neither Bisq or Peach have the Lightning support.

Peach Bitcoin has recently came to the P2P arena. It's app-based (android / ios), easier to handle than Bisq (which runs on a PC). I had a couple of trades using Peach, everything was OK.

To summarize:

If you need the most developed P2P -> Bisq

If you want the easiest app-based way -> Peach Bitcoin

If you want Lightning support -> Robosats