Thanks for the free advertising Bovinespy
@: gdgrimm. Don't forget, expansive also gets half priced Granaries (with Harbour, Organized gets the Lighthouse)

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As to the OP, I have put together a thread which might answer your question, but I have also been working on an interactive spreadsheet which will gives you rankings of UBs, their leaders and whatnot. I added this weekend a section which ranks synergies with your playing style, Civics choices and economies, but I could easily add a map synergy, or that is improve the map dependency ranking that I already had. Look for it this weekend.
I think Mehmed might be good for archipelago, but haven't tried. He is expansive and organized which from what people have pointed out above would be great. He gets 5 buildings at reduced cost. Let's go through them and their advantages.
Lighthouse: On water maps, you want to settle on the coast. Lighthouses give more food from your many sea tiles and needed for the Great Lighthouse which you would most likely not skip if you could help it. It would be a captial offence to settle inland one tile unless for strategic reasons.
Mehmed's extra health comes in handy since your cities will likely grow larger faster from the extra food, at least two from tile, without resources.
Harbour: +50% trade routes, a thank-you. And if you are Hannibal, your Cothon gives youone extra trade route, and then you have the 2 extra from the GL. A huge map with many civs (with hopefully large cities) will give a nice income. (don't forget more health two)
Granary: To help you build up your cities faster and add more health.
Courthouse: As mentioned above, huge deal considering the distance penalties.
Factories: Which as mentioned above, is great on water maps because of the reduced production you will have. I like this fact and think organized getting cheaper factories makes more sense than industrious as they already have the wonder bonus
Oh and the cherry on the ice cream is the UB of the Ottomans, an Aqueduct that makes peeople happy as well, and is only a prereq to the Wonder that begs expansion, the Hanging Gardens, giving you +1 city size and health. Wow time that baby for when you have some newly founded cities and that is a nice boost.
On water maps, I love Carthage and Vikings, but might give Mehmed a try soon.

Oh, and I will wait patiently for a Dutch civ too.
