Beastie Boys (1986)
This was supposed to be on Licenced To Ill but it got dropped from the album at the last minute. The are getting their Beatles on here a little bit.
Big Daddy Kane (1987)
Produced by Marley Marl and features lyrics that eventually ended up on Kane's debut Long Live The Kane.
EPMD feat. LL Cool J (1989)
Different beat and for some reason there is no Erick Sermon. The raps are the same except there is an extra verse by LL on it. Maybe this was a LL Cool J song originally?
Eric B & Rakim (1992)
This is original version with a somewhat different beat. The baseline is absent and replaced by a few different funk samples including James Brown's "Blue's & Pants".
LL Cool J (1988)
This is the original version of "Jack The Ripper". Same beat but totally different lyrics. Not sure if he's dissing Kool Moe Dee on this too, but he's dissing somebody.
Completely different beat (drums might be the same) and features some chick singing on the chorus. Nothing beats the album version though.