What's an off camera brand flash for a Nikon D3000?

What's an off camera brand flash for a Nikon D3000?

Added (1). Is sunpack good. I can only buy this at best buy

More than you can shake a stick at:^)

Vivitar, Metz, Yongnuo, Nissin…

Have a look at the Strobist blog - it's a great resource for off camera flash;
http://strobist.blogspot.com/2006/03/lighting-101.html

the video part way down tells you all you need to get started with off camera flash &the Lighting 101 & 102 Archives in the drop down boxes have loads of gear/techniques.

Edit: Yup, Sunpak are a good make - just make sure it's got a swivel head and manual power output control. TTL (auto flash metering is nice to have sometimes but not always necessary or reliable) and of course make sure it's Nikon compatible!

Sunpack will do as well as Vivitar and Yongnuo.