LOL Critical Beatdown!!! That's a damn good song... if you want something better than 50 cent, look anywhere in the oldskool archives...
But better hip hop that's a bit more recent, well hmm. There's:
The older Mobb Deep albums (Murda Muzik, Hell on Earth, The Infamous)
Gangstarr (A bit of an unknown, but trust me he's good and his producer is even better)
Nas (Illmatic really is the best hip hop album ever)
A Tribe Called Quest ( All of their albums are fucking amazing,they are my favorite hip hop group. Their older albums being great too but a bit dated for the new generation of hiphoppers)
Black Eyed Peas are surprisingly good.
De La Soul (Again a bit more oldskool but I can't stop listening to their "Stakes is high" album)
Ghostface Killah ( In my opinion the best from the Wu-Tang Clan, his albums are all excellent)
Kanye West(Not bad at all!)
Mos Def(Easily one of the best MC's on the planet today... his album "Black on Both Sides" is one of the greatest hip hop albums I've ever heard)
Talib Kweli(Easily up there with Mos Def, their album together, "Black Star" was a masterpiece. His single albums are also incredible.)
The Roots(Excellent live Hiphop act, their MC also is very talented)
Outkast(Surprisingly good stuff from the south!)
I don't know why a thread called "What's your favorite artist" got me to post all of my favorite hip hop artists... however my favorite favorite artist would probably be either The Mars Volta or Incubus