BIG always had the best flow, Tupac always had the best lyrical content.
Woah, woah, woah. Lyrical content?
BIG had the flow, wordplay, and just came out with some stuff you never heard of before. Stuff that had you rewind the song just to check if "Did he just say that?". BIG was WAYYY ahead of his time. And out of both rappers, you definitely hear current rappers copy BIG WAY MORE.
Tupac is in my top 5, but definitely not number 1. His flow was simple, but what saved him/made him unique was his conent(subjects, and topics), and his delivery. Tupac probably had the best delivery of all time, just for the emotion he put into every line.
Two very gifted, young entrepeneurs, that died before their time. You cant compare them, only appreciate 'em. But, if I had to, It's BIG all day. BIG the rapper/entertainer, and Tupac the rights activist/poet.

2Pac was overrated lyrically, the way he attacked a song was fire but the content wasnt that great....Biggie is the best MC ever because he's so versatile and smooth. Any beat, he will kill it.
TP. agree 100%