The first two seasons of VM were my favorite two seasons of television ever. The writing was smart, the characters' interaction touchingly human, and the story lines fun (both the episodic and long arch story lines). It can be cerebral at times and laugh out loud funny others. I have watched the first three seasons back to back four times. I consider myself a true Marshmellow. These seasons were ahead of there time on so many issues. It is fun to watch the "before they were famous performances" of Amanda Seyfried, Tessa Thompson, Kristen Ritter, and Tina Majorino. Ken Marino slays the role of the slimy PI as does Darren Norris the role of dead pan smart-alec public defender. All the minor characters contribute to the overall enjoyable quality of the show VM's Dad, principal, the antagonists, the supporting crew are all great.
Season four was pure money grabbing garbage. Characters whose traits led you to watch the show week after week. (Yes, I used to set my DVR. I am old. I accept it) changed to fit a more female oriented demographic. Which is NUTS because what made the show great was empowerment without condescension and blatant pandering. Not shoving an agenda down the audiences' throat the made the underlying messages seasons 1-3 more potent.
So the first two seasons A+
Third season A-/B+
Fourth season F