Inspirations
The original design is StyleShout's Colourise 1.0, awesome work from Erwin Aligam. I had modified text color scheme and typography to be more legible and more suitable for both Latin and Thai characters (my native).

The first GPL theme by ThemeShark.com

View a live demo

Features:

Tableless design
Strict XHTML and CSS validation
Eight additional and fully collapsible regions
One level of suckerfish dropdowns
Two or Three Sidebars

The Magazeen theme is a cool and modern theme with a stylish colour scheme.

This bold magazine 2-col-theme was designed with the main focus being on
typography, grids and magazine-look. It was created especially for
Smashing Magazine and its readers.

Simply Modern is a table-less, CSS driven design sporting an advanced feature set.

Some of the key features are as follows:

elements via CSS for all layouts (no tables)
14 User Regions
Drupal 6 functionality
Tested in IE 6, IE 7, Firefox and Safari
CSS and XHTML valid
Upload components from ThemeSettings API
Custom Page Background
Custom Mast Head
Custom CSS File
Five preset color options
Copper
Green
Blue
Black
Red
Choose between fixed or fluid widths
Customize sidebar widths
Sidebars can be on the left, right or split for 1, 2 or 3 column design

Clean modern theme with fine tuned css, will be great for blogs, communities and online media.
This Drupal theme was designed & developed by RussianWebStudio.com team.

Features:

Smart 1-2-3 columns
Big amount of regions
Fixed width (from 1024px and greater)
Tableless (css based)
XHTML Transitional valid
Tested in firefox 2+ / opera9.x / chrome / ie6+
Additional quick-links blocks for admin

Genesis is an standards compliant, accessible and semantically rich starter theme for Drupal. Genesis is easy to theme yet extremely flexible, giving you endless theming possibilities. Genesis makes building a standards compliant accessible theme easier than starting from scratch.

Key Features
Standards compliant—XHTML Strict, CSS3
Modular CSS
Flexible layout options
Built in support for theming site sections
Gpanels - multi-column, fluid grid micro-panels
Content source ordered for SEO
No complex logic in templates
Advanced dynamic CSS classes
Conditional Styles module included

Acquia Prosper is an advanced Drupal theme by TopNotchThemes, with a monochromatic look and clean lines. It is designed as an Ubercart e-commerce theme that is easy to customize, but is extremely flexible for any type of site.

Deep mod. Acquia Marina by TopNotchThemes

Features
CSS-based (tableless)
Flexible layout
1, 2, or 3 column
15 collapsible block regions
Funny breadcrumb
Valid XHTML 1.0 Strict
Cross-browser IE 6/7, FF 2/3, Safari 3/4

Fusion is a powerful base theme, with layout and style configuration options built in that you can control through Drupal's UI. It's based on a simplified 960px or fluid 16-column grid. It's designed to be used with the Skinr module, with numerous useful block styles included.

Don't theme yourself into a corner. Our goal is to make Fusion the clear, simple, and supported option for creating advanced Drupal themes.

The Acquia Prosper theme by TopNotchThemes uses Fusion as its base theme.

Zero Point is an advanced theme developed by Dr. Radut to be ideal for a wide range of sites. It contains the same kinds of features you'll find in our other Drupal themes, plus many more.

The theme validates XHTML 1.0 Strict / CSS 2, and it is cross-browser compatible; works perfect in Firefox, IE 6, IE 7, IE8, Safari, Opera and Google Chrome.

Live demos of different sub-themes and variations at: ECOimm, Boaz Broker, to name a few.

Layout features
1, 2, or 3 column layout with adaptive width based on "The Jello Mold Piefecta Layout";
17+1 collapsible block regions;