Killian is one of the original premium WordPress themes released, but has received several updates since then and still provides a great look for a WordPress blog!

Killian 1.0 Theme

Features included with Killian:

• Widget-Ready
• Drop-down navigation for sub-pages.
• Tag support for WordPress 2.3.
• Built-in archives page.
• Drop-down boxes for categories, monthly archives and site tags.
• Gravatar integration on comments.
• Gravatar integration for author photos.
• Multi-author blog functionality.

Killian Prices:

• Personal ($49.00)
• Developer ($159.00)

Source/Demo | Purchase

There are a number of themes which were designed to be variations of the Kubrick theme (the default WordPress theme), but the newest release by the Solostream team is by far the best one I’ve seen yet. 

This new theme, they’ve dubbed WP-Crystal, is a premium blog theme that also can function like a magazine theme. 

WP-Crystal Blog Theme

WP-Crystal Features:

• Widget-Ready, User-Friendly, and Optimized for WordPress Versions 2.2 and Above (including WP 2.7)
• Seven Different Color Options built in plus the ability to customize to your specific requirements
• Threaded Comments With Styling
• Home Page Featured Article Glider Box
• Built-In Banner Ad Blocks
• Built-In Site Guide in Right Sidebar
• Customized Recent Comments in Sidebar
• Author Bio Information and Gravatar Included on Single Post Pages
• Social Networking Icons Included on Single Post Pages
• Alternating Color Comments With Gravatar Support
• XHTML Valid

WP-Crystal Price Options:

• Single-Use ($79.00)
• Multiple-Use ($179.00)
• Developer’s Pack ($279.00)

Source/Demo | Purchase