I love this cover because it's so subversive.
It starts out as a mocking parody of Donovan's original (at least that's what I hear) and that nasty little mean part inside you is like "yeah, OK, let's do this, I'm totally open to making fun of Donovan", and so you start to listen ironically, and slowly, imperceptibly, it flips the script on you and by the end you've been tricked into un-ironically jamming out to what turns out the be a very good Hurdy Gurdy Man cover that perfectly encapsulates what made the original so great.