My picks are going with the crowd:
IV/Security - I love the consistent sonic atmosphere (mainly due to his use of the Fairlight), the integration of African drumming rhythms, and some stellar songs. The Family and the Fishing Net is my one song to skip.
III - The album seems so integrated thematically, with every song touching on some aspect of fear and violence. It also has its own unique sound.
So - Catchy and commercial, but still clever and multi-layered. It has something as straightforward as Sledgehammer and something as left field as Milgram's 37 (although the early live versions are more dramatic).
But there are a few other albums that could almost make this list for me.