Insecure by default

I would like to setup a box on my home network that would be somewhat easy to gain unauthorized access through remote exploits (i.e., not weak passwords, etc.). I've heard of a lot of Redhat 6.2 (default server) installations being used for this purpose. I was curious what recommendations you might have. I would like an OS that has several interesting known exploits from which I might gain valuable experience. Thanks in advance for your ideas.

nt4 has more than you'll ever need but really any unpatched os and a little searching can keep you going for a long time. if your setting up a hacker lab...uh, excuse me, i mean, a security research facility, you should have multiple OSs.