Mainly because that was my early college years and it was when I was really going out of my old element as far as discovering new music. So many of my favorite albums came out during that 2 year period:

Blu & Exile - Below The Heavens
Kanye West - Graduation
The Roots - Game Theory
Brother Ali - The Undisputed Truth
CunninLynguists - A Piece of Strange, Dirty Acres
Lupe Fiasco - Food & Liquor, The Cool
J Dilla - Donuts
Talib Kweli - Eardrum
El-P - I'll Sleep When You're Dead