Come to grenada with exile check out captain Ricky's blog you have a great chance to catch a blue marlin and a white marlin and a sailfish and spearfish in the same day aka super slam and stud yellowfins http://captainrickywheeler.com/grenada/
What time of the year?
Panama, Guatemala & Costa Rica would all work. Check them out at www.tropicalfishing.com
Is it supposed to be all fishing? If it's going to be a vacation with you getting a chance to fish, leave out Panama & Guatemala.
i like thats funny I take time every year for trips to florida , north carolina outter banks, Austraila years ago , Jamaica never been to Mexico heard so much about cabos fish are close to the beach affordable charters . Costa Rico would be cool also need more research
If it were me, I'd go to Bermuda. A great place to go for a week or so. Check out Capt. Allan DeSilva on De Mako. Top shelf guy and great boat. In the summer, large Blue Marlin, Allan has caught more Atlantic granders than anyone else, and also lots of big Yellowfins and Wahoo. http://www.fishbermuda.com/