Wouldn't It Be Nice

This modulation happens within the first 10 seconds (though you should listen to this whole song, and whole album, because they are both awesome):

A conventional four-bar arpeggiated introduction (I – vi – ii – V, strongly establishing a key area) gives way to a wailing vocal that enters a full step above where you’d expected to be.
Rather than intensification (there’s barely anything to intensify), the purpose here seems to be disorientation, and through disorientation, the bold announcement of a new sound that turned out to be a seminal change in pop music; Sir Paul McCartney has gone on record saying that without Pet Sounds, there would have been no Sgt. Pepper.
-Matthew Wrather from Overthinkingit.com

You Better You Bet

I hate thinking about The Who in this stage of their careers. Keith is dead and so was the soul of The Who. Here, Pete uses a key change to give a crappy song more life. Up a step from C to D in the outro.
-Tony Trov

Do You Realize?

Leave it to The Flaming Lips to write an insane key change into an otherwise pop-structured tune and make it work beautifully. Yoshimi Battles the Pink Robots' "Do You Realize" is in C. At 1:59, the key changes to Eb. Twelve seconds later, it goes BACK to C for the remainder of the song. Geniuses.
-Mike

I've Been Loving You Too Long

A jump from A to Bb between phrases on a song with no actual chorus. Take it away Otis.
-Kristen

Dry Bones

As the Delta Rhythm Boys go up and down the skeletal anatomy of the human body, so too do the keys progress from the toe bones to the head bones and back. A true classic in barbershop key changes!
-Johannes Rebane

I'll Never Forget You

One of my favorite songs from last year is the Noisettes' Never Forget
You. It has a great early Motown sound, with a key change from D to E
in the third verse just after the bridge.
-Al Bruno

I Will Always Love You

A classic pop radio key change. Song starts off in A major, at around 3:05, we get set up for the key change with an E major, which then brings us to the chorus in B major. The scene behind Whitney Houston in this video changes as well. Does that mean I get extra points?
-Mike Vivas

Play That Funky Music

The sing along chorus is the key to the masses and no one expresses their faith in this rule like Wild Cherry in Play That Funky Music (White Boy). Like many of us who thought rock and roll was the easiest type of pop music, they discovered that they were dead wrong. Funk is super easy, similar, and at the time more lucrative. In this video, you'll notice the coolest horn players ever, the weirdest outfits white people ever wore, the corniest looking drummer of all time, and a key change or two. Not only does the key change on the choruses and at the end it goes up on the outro (twice on the recorded version, once here). Big ballin.
-Nick Anastasi