As you all have noticed Em has mentioned Tupac in plenty of his songs/freestyles so why not make a complete list out of it. I'll start with few and then you guys add some more (you may also add the line/s itself if you want to):
If I Get Locked Up Tonight
Patiently Waiting
Get You Mad
Busa Rhyme
Just Don't Give a Fuck
Square Dance
Til Hell Freezes Over
Soldier
Fubba U Cubba Cubba
Marshall Mathers
'Till I Collapse
Our House
Scary Movies
Hailie's Revenge
That's the full list (so far) and that's a lot if you ask me. Not that there's something wrong with it though.