Neversoft's motto with GH seems to be "If it's not played with guitar, make people play it anyway and make it a massive chord". (FYI, the final note in Raining Blood is a thunder sound effect.)
Anyways, I pooped yesterday when I saw Suffix's TF2 map. It is straight sicknasty, yo. This may just be because I've never made a Source map more ambitious than a big gray room full of HL2 zombies, but I'm extremely impressed; we're talking Valve-quality stuff here.
Also, I minipooped when I found out "Phydo" is a pun on "Fido".