If you are an expert or a novice DotNetNuke developer and you have a budget of under $100 I recommend the following skin.  The included EasyMod module allows you to change the color and size of every object on your DotNetNuke installation without being a CSS expert.

Flex2 By DrNuke + EasyMod Module - http://www.drnuke.co.uk/Products/Flex2/tabid/3363/language/en-US/Default.aspx
Price: $99.99 - http://www.snowcovered.com/snowcovered2/Default.aspx?tabid=242&PackageID=14361

Features
* Any COLOUR!
* FREE EasyMod module
* W3C Valid XHTML/CSS
* 10 menu styles
* XML flash banner
* 100 banners
* Library of background images
* Completely customisable!
* Full documentantion
* Cross browser tested
* PSD files included
* Custom flag icon pack
* Exceptional support
* FREE lifetime updates
 

EasyMod print screens