... when you get a CD copy or a 'Deluxe Edition' of a classic album you know, and to fill up the disc they've stuck some studio out-takes, demo versions and alternate mixes on the end which mess up the flow of the album, and in almost all cases there's a reason they weren't included on the original album in the first place - they're not really very good.
But there are some exceptions... I'll start with -
Fleetwood Mac - Silver Springs (on Rumours)
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Just because I don't care, doesn't mean I don't understand." - Homer Simpson