With Warlords I think the Great Wall is an awesome wonder. More so for the Great Engineer points rather than the defense (which is a HUGE convienence for me). On earlier difficulty before Warlords I would often build Pyramids for the GE, since I never ran specialist economy. The GW is 200 hammers cheaper, saves you extra hammers and hassle because military is less of concern and using the first GE for Hanging Gardens in the same city is great. Stick Parthenon in another city if possible and lots of GE's. In my recent game with Stalin I had TWO GE's with nothing to do in the medieval era (admitedly I was industrious and had stone) but it was great. An underrated wonder. (perhaps with philosophical leaders you can get Pyramids quicker by using GE from GW, then using next GE for Great Library for specialist econ.) The only must have wonders are Pyramids, Great Library and SoL when running specialist economy. Other wonders are great convenience. Uni of Sankore is awesome with Spiral Minaret and Religion whoring (perhaps thats an inappropriate term lol). Stonehenge is useful and Stonehenge+Oracle+religion is good too. Colosus and Great Lighthouse are huge on Archipalego and I always get Three Gorges Dam if I can. Temple of Artemis+Angkor Wat+reglion is useful, better if you somehow slot Pyramids in. Perhaps Ironworks is the only must have really. Ironworks+Heroic Epic =overkill. EDIT: Regarding the Great Wall w/Hanging Gardens, HG is so cheap you may not need GE for it anyway.