Rappers freestyling is alot different from a rapper just rapping and though there are many good rappers there are not a lot of very good freestylers. Here are my top three free styles in no particular order...
Big L, 98 Freestyle...The only freestyle I can recite word for word and thats saying something BIG L R.I.P
Charles Hamilton...Even though this cat fell off the map he still holds a special spot in my heart because I know he still hasn't released his full potential, He ridiculously talented to bad hes crazy.
Eminem...This isnt the most known free style around but eminem is hilarious on the mic and rips it a new asshole, strait up off-the-top freestyle