To wacken mostly:
The Iroquois used to be my Civ of Choice for Sid Pangaea maps. Now, I have switched to the Greeks and feel that I have more success with them, might be just my style of play. Success used to be very much based on getting the GL (building or capturing).
Usually my scientific aquisition goes something like this. Contacts are acquired ASAP, then hopefully the Alphabet (being an expensive tech) can be traded for some of the other opening techs. When writing is researched (at min.) most of the others usually have it, but I can usually trade it to some laggards. Research literature at max, big question: possible to build GL? Usually no, but literature can be traded even for expensive stuff like Construction if you have monopoly. Big problem: how to acquire Republic? Self research is usually too slow and it is too expensive to buy. Solution: scientific trait.
For lower levels I still prefer the iroquois. If you do not like commercial, the Sumerians are pretty great too.
On archipelagos I wonder why you would choose agricultural. Might be I would change my mind if I played larger maps, but the archipelagos I am dealt tend to have very little fresh water, an extra food after changing to Republic is of less importance. Also, seeing as one usually plays Archipelagos to get isolated starts, one also has more time to fill the local lands before the AIs come knocking. Therefore an extra food in the capital is less critical.
Trading is easier and research tends to go slower on archipelagos so I feel scientific is less needed than on pangaeas, therefore I prefer the English.
All this might just be a matter of style though.
P.S. Doc T. started quite an interesting thread about ranking the Civs which spawned a long discussion on civs and civ traits:
http://forums.civfanatics.com/showthread.php?t=104658&page=1&pp=20
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get your facts together Wacken 
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