The relatively new song, Breathe, by Fabalous samples the lyrics
"Breathe" from an older song.  What was the original song?

The song samples Supertramp's Crime of The Century.  According to a
post to rec.music.hip-hop, Ray Lavelle says "I know the actual
original sample doesn't say 'BREATHE'... Just Blaze changed it so it
sounds like 'BREATHE'..."

Although I'm a Supertramp fan and have heard the song numerous times,
I can barely recognize it in "Breathe."  That is why I think Mr.
Lavelle's comments are likely true.

Sources:
-Article stating that the sample is Supertramp
http://www.musicomh.com/singles2/fabolous.htm
-Ray Lavelle's USENET post on Google groups
http://groups-beta.google.com/group/rec.music.hip-hop/browse_thread/thread/ff31f6afb7d84d32/6cae9ea8c3c8b276?_done=%2Fgroup%2Frec.music.hip-hop%2Fthreads%3Fstart%3D550%26order%3Drecent%26&_doneTitle=Back&&d#6cae9ea8c3c8b276
-Allmusic's Page on Crime of The Century 
http://www.allmusic.com/cg/amg.dll?p=amg&sql=10:aek0ikk6bb79
-Vibe Magazine page where one can listen to "Breathe"
http://www.vibe.com/modules.php?op=modload&name=News&file=article&sid=461&mode=thread&order=0&thold=0

I hope this helps.