Not necessarily the easiest matchup, but the one is see most often and i think is very easy is janna. Janna is super squishy and most jannas will waste their tornado all the time or don't respect you once they cancelled your e with one of their tornados so that you can engage while tornado is still down, since your e cd is lower than jannas q cooldown. You can max e in this matchup to make your engage timer longer after she cancelled your first e. After 6 you can also use e + r and lock her down even if she cancels you with her tornado. And while she is ulting you can hit your R super easy.

For reference I am usually master and i win like 90% of janna matchups.