Albums that you know are going to be brilliant within the opening 20 seconds of the first track

Royal Trux - Sweet Sixteen

Opening 20 seconds: Matthew Sweet, Girlfriend - swirling guitar effects resolve to a confident psychedelic blues. It had my number.

Opening 2 seconds: Tom Waits, Rain Dogs - (Squawk!)

Royal Trux - Sweet Sixteen

the Pussy Galore is better :D ;)

Opening 5 seconds: Destroyer - Streethawk

Opening 90 seconds: Can - Future days

Rain Dogs yes. I can remember the moment! My friend slapping it on the turntable, me vaguely aware of Waits as a seventies singer songwriter of some kind, maybe like Randy Newman. The squawk like a closet door opening, all these strange tools stuffed inside clattering to the floor