Hi! When he’s not working on movies his favourite hobby is definitely music - especially playing the guitar (see this website for a list of his musical history: http://www.deppimpact.com/musicindex.php). He listens to and appreciates a lot of different genre types and artists (too many for me to list here) but you can visit this great site for more information regarding Johnny and music: http://www.johnnydepprocks.com.
I do not know either Johnny, Helena or Tim personally (I wish!), this is just a fan site. Hope I answered all your questions, have a great day! :)
Season 2, Episode 22. Judy actually responds with “Mel Gibson” in the episode, but I modified it. :P