Ubuntu, because snaps break shit and don't work right a lot of the time, also they left people hanging with 32 bit support which isn't great (for being a Legacy OS for weak computers it's not a great look for them, or all the Linux distros that followed them).

There were a lot of problems with Fedora and CentOS, none of them as bad as Ubuntu though. Most were either instability or software availability due to lacking RPM versions of the software I needed.

Arch itself hasn't given me many problems but it is ideologically problematic for a lot of reasons (mainly the elitism) and it is also a rolling release which isn't great if you don't like being a guinea pig and getting software before all the bugs have been ironed out.