Whenever in one of my games I get a ship of the line, my next line of business is capturing a Royal Sloop to serve as the second ship in my fleet. A SoTL is able to take out just about anything... Except those annoying peace offers and smugglers. I use the SoTL for most of the heavy lifting, but when I feel the need to get a war canoe, keep countries at war or take otu a smuggler carrying thousand of gold, I just switch to the Royal Sloop. Using both only takes away twelve crew. Eventually as I am able to get in the upper 400's in crew without mutiny (due to my 500,000 odd gold ) I also get a one or two English Large Frigates, courtesy of a pirate hunter so that if my SoTL takes 30 or so shots, I can just switch out and continue plundering, which is especially useful for plundering the treasure ships 
So really, there needs to be no debate about whats best, because you can use any together.
Also what ship/s do you guys like using through your games regardless?

So really, there needs to be no debate about whats best, because you can use any together.
Also what ship/s do you guys like using through your games regardless?