The bigger the better I think. The bigger ships are designed well & don't give the impression that they are huge. Caribbean is great, although in October you are just within the last month of the hurricane season (until aprox November), although the ships are very adept at avoiding them & re-locating to another island. The Caribbean islands are very 'user-frindly' & generally there is no need to buy the ship's own tours, just get off & do your own thing. The med is fascinating, but because the ports visited are sometimes a good 2hr coach journey away from the ship, this means that you are probably better off bying the ship's own tours, which can prove costly. Depends how young or young at heart you are. generally, the Ocean Village-type are for the younger/energetic set, NCL for complete freedom from formal wear,Princess for US-style ships with Britishness, RCI for ships in the middle of the last two, Celebrity for being treated like royalty while not paying the earth for it. Ships companys not mentioned we have not been on.