Across four albums, Mobb Deep's primal realism vaulted them amongst hip-hop's biggest names; they rap-battled with Tupac and rhymed alongside Nas, B.I.G. and the Wu-Tang Clan. But with one verse off of his 2001 diss track "Takeover," Jay-Z made crystal clear what many were reluctant to admit: the Queensbridge duo of Havoc and Prodigy were getting stale.

Now though, Mobb Deep is seeing their paper stack as a part of 50-Cent's G-Unit. Unfortunately, the role calls for Mobb Deep to act like Tony Yayo and the rest of the G-Unit goons: mindless gun-toting, money-flashing drones parading over expensive beats.

Mobb Deep's new greatest hits album, Life of the Infamous: The Best of Mobb Deep, illustrates this unique career trajectory. We spend the first nine tracks in awe of that ominous streetwise sound that epitomized the Mobb in their prime and drove mid-'90s east coast rap.

Havoc-produced "Shook Ones Pt. II," from their sophomore album, The Infamous, is the strongest track here. Driven by a sinister synthesizer loop, the track is a haunting reminder of how far Mobb Deep has fallen. Though much of their subject matter remains the same, here Prodigy and Havoc drop contemplative jewels, not empty threats. Alongside the gun talk we have Prodigy rhymes like, "I'm only 19 but my mind is old / And when the things get for real my warm heart turns cold."

Outside of Alchemist-produced "Win or Lose," the remainder of the album leaves the listener in the post-Murda Muzik gutter into which Mobb Deep's career fell. Did that bulletproof-vested egomaniac force Mobb Deep to remain on this path or was it Prodigy's slide from a lyricist with Ginsu-like sharpness to a mumbling nonsensical shit-talker? I want to blame 50, but the evidence is here, and the Mobb's artistry undoubtedly gave way before they became G-Unit soldiers.

Quite opposite from Mobb Deep's trajectory is the path of former Goodie Mob frontman, Cee-Lo. Best known for his pairing with Danger Mouse, Gnarls Barkley, Cee-Lo is just moving into the public eye after over a decade in the game (excepting, of course, his appearance on My Super Sweet Sixteen).

While label problems forced Cee-Lo off the roster as the third member of Outkast in 1994, he found success with Dungeon Family affiliate group Goodie Mob. In 2002, Cee-Lo expressed his soul prowess on Cee-Lo Green and his Perfect Imperfections; and in 2004 came back strong with the masterful Cee-Lo Green. Is the Soul Machine.

Yes, that's it. The man has two solo records and apparently this merits a greatest hits compilation. Problem is, his albums are so successful as cohesive pieces that, out of context, the songs suffer. New fans are better off seeking out each album individually than finding them awkwardly thrown on this collection.

Because so much collaboration goes on within the hip-hop community, label obligations restrict "best ofs" from fully representing an artist's best work. Still, these are two hip-hop vets with impressive discographies in their own right.

Peep the Mobb Deep; cop the Cee-Lo solos on the low.