5. Will Smith & Tommy Lee Jones
When it was revealed that Jones would play little more than an extended cameo in MIB 3, it was easy to feel sceptical that such a move would go down well with fans of the first two films who enjoyed the chemistry between the two. One of the more popular aspects of 1 & 2, whether you liked the stories/plots or not, was the age old combination of youthful inexperience and seasoned professionalism that worked so well between J & K. Tommy Lee couldn't have been better as the grumpy old agent with little time or patience to take his eye off the ball. Smith brought the energetic charisma to the role of J, often providing his best humour at the expense of his ancient partner. Luckily, the disappointment of Jones' absence for the majority of MIB 3 was effectively diminished by the surprising likeableness of Brolin in the role of a young agent K, which we'll cover more in the next point. However it is unlikely that such an absence will be so easily deflected in a future film and given the aforementioned chemistry between Smith & Jones, audiences would dearly love to see the two reunited on another adventure together should the fourth instalment become a reality.