Similarities of ENTJ's and ENTP's:
+ Both make primarily intellectual jokes
+ Both are dead on.. deductively accurate
+ ENTJ jokes are more opinion-based
+ ENTP jokes are more socially acceptable (toned-down), that's how we can insult someone, but in a playful way.. ENTJ's don't insult playfully, they pulverize.
+ ENTP's joke more often.. practically all the time.
+ ENTJ's are more serious and their jokes are more subtle, yet direct (it's harder to decipher when they are joking, generally)
That's really all I can think of right now.