I'm using Infomaniak. I especially like their renewal warranty [0]. It's a few bucks more a year but they renew the Domain even if you are not paying and try to contact you by phone, snail mail etc. They also support IPv6 and DNSSEC.

[0] https://www.infomaniak.com/en/renewal-warranty

I used to be on Versio, but moved to TransIP after the acquisition of Versio by TWS.

TransIP is not exactly the cheapest, but they work fine. Vimexx (which is under the same company as TransIP) is cheaper (closer to pre-TWS Versio pricing), but I'm a bit hesitant to trust a 'budget' registrar again.

Not sure if it meets the European criteria but I use a combination of DNSimple and Porkbun and am very happy with them both.

For less common ccTLDs, Gandi is still hard to beat since they support virtually everything. Apart from that, I have no regrets moving... I saw the writing on the wall about 2 years ago and moved virtually all my domains away from them.

I wish I had something useful to recommend now, but we've only just started looking.

I use INWX for some years for 2 domains and can't complain about anything.

I'm happy with INWX

I am happy with OVH. Only bit that’s missing is IPv6 for dynamic IPs.