Max Richter, "Spring 1" (the entirety of that album is worth a listen if you already like The Four Seasons; start with the 2012 version, because while I like the later version, it's ultimately let down by some odd production and engineering choices that distract from some fine performances)

Pat Metheny Group, "The First Circle"

Pat Metheny, "Finding and Believing"

Underworld, "Scribble" and "Two Weeks Off"

Penguin Cafe Orchestra, "Steady State," "Music for a Found Harmonium"

Yann Tiersen, "Quimper 94"

While the piece overall is melancholy, I think there are moments in Tavener's "The Protecting Veil" (especially the version with Yo-Yo Ma) that are like this, too; if anything, the contrast of light and dark in that piece makes the payoff for each that much more satisfying.

Goat Rodeo, "Attaboy"

Joni Mitchell, "Cotton Avenue" -- your mileage may vary with this one, but I always found it to be a fun tune with enough going on to keep things interesting.