I started out playing games on medium sized continent maps.
More recently, I've played a couple games on duel Pangaea maps, starting in the medieval era,
and found that I really like the pace...
-You start with 2 settlers, 1 worker, 2 spearmen and a scout.
-All techs up to the medieval era are researched, so you see iron/horse right away.
-The production costs are different: most units and buildings are cheaper than on a normal start, but settlers are much more expensive.
-Most of the purchase costs are higher than normal.
-Techs have a cheaper that normal cost, but your economy is also much less developed. The upshot is that it takes longer than usual to research the medieval/early rennaisance techs, but the later techs are faster.
-You start with enough culture for three civics. (This may be a bit broken: You can get the +3 production in coastal cities right away...)
Pangaea on a duel sized map seems to generate some pretty cool geographies:
-one game had an Australia shaped continent cut in half by a mountain ridge
-another game had a horseshoe ('U' shaped) continent, with one of the city states (Sidon) separating the two sides. There were also a couple of high yield islands.
P.S.: standard game speed, emperor difficulty