300 Bars & Runnin' 

A song made by The Game, where he disses 50 Cent and the whole G-Unit, including Olivia. The song is called "300 Bars & Runnin'" because he raps 300 line breaks non-stop with several different beats (including Jay-Z's "Takeover" and Kanye West's "Diamonds From Sierra Leone"). The song is over 15 minutes long! He basically says everything he wants to say about the whole G-Unit and answers their insults against him.
Some say this song was so heavy it made 50 Cent pull out of his beef with the Game. All the rappers in G-Unit Records made a song called "300 Shots" later, but it was insignificant.

300 Bars & Runnin'
Just loan me your ears for 15 minutes
Walk with me

Here the breakdown, pass the doja, .45 in the holster
Hollow tips'll fold 'em, them niggaz they toy soldiers
Oh, that boy colder than Hova unless he sober
Like I'm the president, but this ain't the takeover
(...)
Bitches only for your shit just a lil bit
Niggaz only for your shit just a lil bit
On my album 50 helped me just a lil bit
Only on two songs, now back to some killer shit
(...)
Now I'm running out of breath, like I just beat boxed
Got 20 bars to go, lay it down like sheet rock
Don't worry about the flow, the boy know he hot

300 Bars & Runnin' by Captain Sham November 22, 2005

300 bars and running 

A 15 min. song by The Game that disses G-Unit, Joe Buddens, DJ Whoo Kid, etc.

So I climb the mountain top and put my stake in
Got the weight of the world on my shoulder
Not a nigga nor a hoodrat bitch can stop me from taking it over
This is crack music, go get the baking soda
300 Bars and Running, nigga the wait is over
I'm gone...

300 bars and running by Da Spik July 29, 2006