My favorite collection of themes is by ThriveThemes which are built to convert.
A fully featured marketing theme with a bold, flat-design style, multimedia post formats and more.
See Squared in action here.And here.
Minimal in design, but packed with features. The theme is highly adaptable to almost any purpose and any brand (especially when you start using our theme customization options).See Minus in action here.
Impressive and functional design. A stylish, flexible and conversion focused WordPress theme for your blog or business. (This site is designed using Pressive.)
Also see Pressive in action here.
An elegant and effective theme for blogging, affiliate marketing and other online businesses.