"Enjoy the Silence" (Depeche Mode)

When Depeche Mode's Martin Gore wrote "Enjoy the Silence" (1990), he envisioned something acoustic and spare: a lone voice and a harmonium, delivering an intimate lovers' prayer from the sanctuary of some ancient church.  That version of the song actually exists, in fact.  It wasn't until the band's producer, Flood, and keyboardist Alan Wilder suggested that the melody could use a beat, a bassline, and some guitar that the familiar version of the track from Violator began to take shape.  Although Gore was reluctant at first to have them screw with his original concept, by the time he'd added that indelible guitar riff, he realized that they might have an actual hit song on their hands.
I recall "Enjoy the Silence" being like a breath of fresh air in 1990.  In the midst of having Hammertime and the last gasp of glam metal shoved at us by MTV (Warrant and Winger, anyone?), suddenly there was this mature ballad out of left field with a soulful vocal by Dave Gahan.  It was Gothic yet somehow bright, and it had this danceable feel—the kind of deep groove that Downtown Julie Brown should have been wubba wubba wubba-ing all over on Club MTV.  On top of that, its artsy video of a king wandering the world, just looking for a place to sit and "enjoy the silence," was a complete departure from parachute pants and teased up hair.
The fact that it became a Top 10 hit and the band's biggest-ever single in the U.S. kind of proves that everyone was ready for something different.

"Policy of Truth" (Depeche Mode)

Depeche Mode's album Violator (1990) sort of created a genre of its own.  It wasn't quite synth pop, even though there were quite a few synths and electronic elements in the mix.  And it wasn't quite alternative rock, even though there were electric and acoustic guitars on many of the songs.  It had its danceable moments, with thumping beats and production touches that made it feel club ready.  But it was too dark and dramatic to be a straight up dance record.  
(I am still surprised, actually, that Violator didn't spawn more imitators, considering it sold 1 million copies upon release here in the US and got tons of airplay.  Usually, that would send every record company scrambling to find/create the "next Depeche Mode.")
The album's third single, "Policy of Truth," definitely leans toward the danceable side of things.  Lyrically, it's a harsh critique of someone (it could be first or third person) who never seems to know when to keep his/her mouth shut.  Musically, its an R&B-tinged jam with electronic beats, percussive synths, and a poppy melody that keeps the track buoyant and immensely catchy.  More or less, it's songwriter/band member Martin Gore's heart-on-sleeve amalgamation of Motown's Holland-Dozier-Holland and Kraftwerk.
I'm especially a fan of the little production touches, like the swooping synth that pans from the right to left channel on the instrumental hook, and the thunderous bass hum that roars beneath the burbling synths on the break from 2:22-2:56.  (If you've never listened to this song on a decent car stereo, do it.  The panning effects, separation, and raw bass will make you feel like you're sitting in the middle of the recording studio, hearing the song performed live.  The mix and mastering on Violator are something to behold.)