I love it for the sheer customizability. I have downloaded more packs than I probably should have, including, but not limited to

-Scout's Mother

-TF2 weapons for use in-game, not just props (includes a fixed shotgun skin)

-A weapon that essentially makes me Dr. HAAX

-The Combine Female Assassin, cut from HL2

-A Combine NPC pack, including Striders

-District 9 MNU vehicles

-And something called VMod, which includes possibly my favorite american sports car, the Ford Mustang Shelby GT 500.

<3

Oh, and heads-up, the blue font is only for Aperture Science entries.