This crime has already been solved, but the Powers that Be don't want you to know the answers...yet. That said, I agree that until that time, we should look to those who had the most to gain by JFK's murder. That is a sticky question. I'm sure that many entities were toasting the event of the day, even if they had no involvement whatsoever. The CIA, LBJ, Castro, The Mob, The Militery-Industrial Complex, and several others including the husbands of women that JFK had his way with.
I have my opinion, but like all of you, it is based on incomplete facts.