Well if your a Apple user (would expect most ppl on this forum would be) you already have a pretty good one pre-installed on your iPad/iPhone and it syncs with your Mac and icloud web version and it only getting better with the next update
I would say Notability, as that's the one I use all the time. But recent updates have wrecked the app for me, although I do like the Google Drive syncing, which works well. I might tryout Goodnotes 4. (Might me the wrong name, sorry)
I have Evernote bundled on my Note 12.2 tablet which seems ok but I've no real call to use it, I could see it being handy with the S pen and my Logitech k810 keyboard in that scenario but really I just don't need to take notes. Only really posted because I see evernote being hyped up everywhere but I've never really seen a use for it personally but it may suit your purpose.
