I'm Every Woman

A  Chaka Khan cover, the proof is in the pudding.
-Nicole 

One Moment In Time

Right after 3:22...booo-yah!!
-Kristine

Gonna Have A Funky Good Time

Heard this at work on  the soul Sirius station.  There are many versions of this song on YouTube but it took me a while to find the full version.  Most versions fade out at 3:30 for radio or Soul Train standard format but in the original the key change comes at 3:47 when James asks the band to bring it down so he can get funky deep.
"We gotta get down and in order for me to get down we have to get in deep." - Sir James Brown
-Nick

Con Te Partiro

Made famous by Andrea Bocelli during PBS's 1997 holiday membership drive, "Con Te Partiro" features a key change just after the midpoint. Here is a wonderful Spanish-translated rendition of the song, "Por Ti Volare."
-Al Bruno

The Youth

Fantastic key change in this song at 2:36.
-Owen 

Always Be My Baby

I heard this at karaoke.
-Alan Smith

Got To Be Real

This funky disco classic with a key change at 1:40 after the break
that kicks the intensity up a notch.  The bass line on this is funky
ass Mrs. Wilkes collard greens.
-Nick