Jay-Z better than 2Pac? No chance.
EDIT - Raw skills then Biggie is better than 2Pac but 2Pac made better music. And was better with lyrics (his poetry showed imo.)
Biggie could never write something like this:
http://www.youtube.com/watch?v=47isVenV0-0
or
http://www.youtube.com/watch?v=NRWUs0KtB-I
or
http://www.youtube.com/watch?v=VCEmTaWSPTk
or
http://www.youtube.com/watch?v=Mb1ZvUDvLDY
or
http://www.youtube.com/watch?v=yWYwGXEsyAc
And as for Jay-Z...