iSkin mini Wild Sides (Diva) for iPod mini 4GB/6GB
I love this cool looking i-skin.  I tend to drop things often.  This is the perfect protection for my ipod mini.  It has nice grips on the side, as well as protection for the screen and click wheel.  It also has little holes in the back, so it doesn't overheat.  However, I do have a hard time to shut it off, sometimes, because of the clickwheel cover.  But as far as sliding your finger on the click wheel, that works fine.  The cover is very thin.