Pyramids - only build them as Americans, +1 city cap and cheaper cities really helped early games
Colossus - great wonder to have, wealth + wood bonus, extra pop cap, worth the investment
Hanging Gardens - i sometimes build them, especially when playing americans, 200 wealth 200 food for +50 knowledge is a great investment, not to mention it save you a lot of resources upgrading your economy(and you could make a bigger army maybe)
Terra cotta - worst wonder, i would build some scholars and citizens instead.
Forbidden city - that could be a life saver when nuclear war started or you are surprise-attacked, a very special wonder, i build them sometimes just for building another university though.
Ankor Wat - one of the best wonders to have, cheaper barracks units,ships,siege units and metal bonus(which you definitely needs for tanks/ships/cavalry/heavy infantry)
Red Fort - too expensive, maybe building them as british is more helpful
Colosseum - i only build this when i want my enemies to have fun with attrition
Temple of Takai - i hate this wonder
Versailles - great wonder to have
Taj Mahal - you need invincible cities for nuclear wars.
Statu of Liberty - not especially useful compare to other wonders, i quite like the bonus though, counters those damn Russians.
Kremlin - great wonder to have good economy, the +1 free spy just make it more awesome
Eiffel Tower - when i lacks oil, rarely built them, i prefer spending on a few more oil rigs/cities with refineries, however, it's a tough wonder
supercollider - i used to stack up loads of unused wealth, this wonder could be good, instant research is great too, especially if you libraries keep getting bombed, but they are too expensive in case i have too many wonders around
space program - it's important to know where you should fire your missiles and nukes, cheaper planes makes it even more awesome.