responsive theme with sass/compass
Chrysalis is a modern looking theme which supports the Asynchronous module.
"analog" ausschauendes drupal 6 theme
Genesis is an standards compliant, accessible and semantically rich starter theme for Drupal 6. 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.
Wabi theme is a original recolorable theme for Drupal 5.x and 6.x