Maya and Rome first came to mind when I read the topic title, so I can back up both of those. My personal favorite is Maya. The amount of gameplay options you can open up in the early game with GPs is incredible.
Early Theology rushed with Great Library, Liberty Finisher rushed with Oracle, and Leaning Tower? More GPs than you know what to do with, seriously. Yeah it's suboptimal if you want to amass GSs, but it's fun as hell.
My most recent Maya game went like this:
Open Liberty, Scout, Monument, Pyramid, Great Library (Philosophy), National College, Theology, Oracle, Liberty Finisher (GE), Rush Chichen Itza, Rush Leaning Tower, Rush Porcelain Tower
Seriously, it's dumb. You can get an early GS to keep slingshotting techs, snag an early wonder or get massive production from a manufactory-hill, found/enhance a religion around turn 70 (standard speed), and the GA and GM serve great purposes, too. The fact that you play against humans makes key wonders easier to get, but it does make you more susceptible to early rush, so it really depends on what your friends' playstyles are like.