From MediaMonkey Wiki
Many skins have been made for MediaMonkey, and the list is getting bigger every day. MediaMonkey 2.x used Winamp Classic skins as a basis for the player skin, which allows for hundreds of skin variants. However, MediaMonkey version 3 uses a more powerful skinning engine, allowing skin designers to implement more creative skin designs. Use of Winamp skins (either 'Classic' 2.x (.wsz) or 'Modern' 3.x (.wal) is no longer possible.
Note that only when using skins that have an included 'mini-player' format will the mini-player option be accessible from a button in the upper-right corner of MediaMonkey (adjacent to the minimize, restore, and exit program buttons).
User's Skinning Project Skin
How can I make my own skins?
Skins are easily created using (ThemeEditor). If you're not familiar with it, or need a bit of documentation re. how to get started, check out these pages:
Where To Get Skins
If you just want to download skins that have already been created, see: