Preferences are ranked in order top to bottom:
Over-all: 3, 1, 2.
Color Pallet: 1, 3, 2.
Navigation & access to content: 3, 1, 2.
Sells your product and/or site: 3, 1, 2.
In this catagory, design three is much farther ahead of the others. One key item are the prompts to Join.
"Clean Look": 2, 1, 3.
Basically, the third design gives the feeling of being able to jump right in and get at the content. Plus it prompts the user to "get involved NOW".
The only drawback was the color pallet and the graphic "chatter" in the top of the page for design 3. A little clean-up using a pallet similar to design 1 would make it a killer design (I would keep the red or other unique color for the "Join" buttons, however).
- Tom