Def Jam Rapstar
51 Achievements
PS3
You Be the Judge
Rate a video on the Community
5.5%
How to unlock the You Be the Judge achievement in Def Jam Rapstar - Definitive Guide
ChrisD0811
From the main menu, choose "Community" and then scroll down to any of the three options below. Any option will do. Choose any video with 
, and then press 
to bring up the "Rate" option. Give it however many stars you would like, and press to confirm. The achievement will pop immediately.