I'm with Kevin. It's important to define the terms these days.
Underground -- secret and unrecognized by anyone.
Off campus -- recognized by the university, just not big enough to the point that they have a house on "greek row."
Unaffiliated -- this is the Michigan situation. They are not recognized by the university but have their own IFC and are part of the national chapter.
To me, you want to find the most stable situation you can. Underground would be a no -- unless I formed my own "underground frat" with my buds. ITK
