I like beginnermen. They're just white endermen with blue eyes. And the best part is: I made them! Just search "beginnerman" on the Skindex and they should come up.
I like frog based skins. http://steamcommunity.com/id/ghilliepanties/screenshot/470860782124835795?tab=public http://steamcommunity.com/id/ghilliepanties/screenshot/594709500195880670/?tab=public
I don't know where my Vault Boy skin ran off to, it makes me sad. I'll find it eventually though, and I'll equip it again.
I Switch up my Skin all the time, But right now it would have to be the one I'm using for my friends storyline server, The Ender Mage.
I hardly ever change mine. I've only changed it once, and that was from my Enderman Commander to my current skin, the Beginnerman Commander.