Any Free Vulnerable Distros for Me to Mess With?

Dear inhabitants of Null Byte,

I am currently in the process of setting up a pentest lab to play with.

As of now, I have a Windows XP VM, Metasploitable 2 and an old Windows 7 Laptop that's just begging to be p0wned.

Does anyone know of any other free, deliberately vulnerable VMs I can download and practice on that are similar to Metasploitable?

Cheers.