Gimme More is the obvious best track, but the album has enough to sink one's teeth into. Piece of Me has follow up single status and has biting lyrics more Pink than bubble gum. The chicken sound actually fits in and gives the song a sound that could provide future sampling opportunities as it is so unique. Radar also deserves some play alongside Cold as Fire.
The rest of the album isn't filler, but it's not stand alone either. The last two tracks slow the album to a crawl, which clearly disrupts the more dance-genre sound Britney moved toward.
Final Note
LOVE