Great, they're probably most similar to more personal town sims like Banished or The Guild, maybe a little Black and White.
5 is all you need out of the previous 3, but I'd still recommend getting the Tropico Reloaded pack next time it's on sale for 2, since it's the one that wasn't like the others - have you a little pirate shanty town :D
Vanilla 4 is the same as 3 but with no noticeable graphical improvement. All the DLC for 4 make it a great game. Tropico 5 is a complete revamp and looks like once they're done with the DLC it will be a gem.
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