Deepest Purple: The Very Best of Deep Purple will perfectly satisfy anyone wanting to discover Deep Purple without shelling out for the comprehensive, four-CD box set Shades 1968-1998. Deepest Purple has it all: undisputed classics ("Highway Star," "Child in Time," "Space Truckin'," "Woman From Tokyo"); prime samples of the David Coverdale-fronted Mark III lineup ("Burn," "Stormbringer"); unreleased European singles ("Strange Kind of Woman," "Demon's Eye," "Black Night"); and, of course, the mother of all guitar riffs, "Smoke on the Water." A perfect summary of the band's '70s heyday. ~ Eduardo Rivadavia, All Music Guide
I agree, too, that Child in Time is epic--what a great tune! Interestingly, I've been recently listening to the album by the band It's a Beautiful Day that has their big song, "White Bird" on it. There is a song on there that has the exact same main riff as "Child in Time."
What sucks about this album is that the vinyl version has far too many minutes on it per album side, resulting in atrocious sound quality. You have to crank it all the way up to get any kind of volume on it, and then it sounds muddy. This might be that rare case when I have to "upgrade" a release from vinyl to cd in my collection.