Mausoleum at Halicarnassus +1: The only wonder I always try to snag. Isn't really dependent on RNG placement restrictions (can be built next to coast or next to a lake if inland), and it's nearly always available for some reason as the AI does NOT like to build it at all. The extra engineer charge can be near gamebreaking on the right engineers, and the tile yields are by far the most powerful of the "Petra-style wonders", boosting your science, culture and faith by a significant amount at the time where it counts the most. Double charges on Sergei Korolev (instabuilding both Earth Satellite and Moon Landing), Alvar Aalto or James Watt? Yes please, always!
Pyramids -3: This wonder is a little overrated in my opinion. Let me be clear: Yes, this wonder always pays off, and is good. But what does it really pay off besides the investment? Paying off the investment is a prerequisite for even building a wonder, but that's the only thing this wonder does - paying off the cogwheels for slightly more cogwheels. After Feudalism (and possibly with Liang appointed), your builders get 5 or 6 charges baseline anyway. Will it really matter by then if your builders have 6 or 7 charges instead? Again, this wonder pays off the investment, but it's not propelling you into an ultra-strong game, unlike the Oracle (which can guarantee you most of the early GS/writers, and saving you a ton of faith), the Mausoleum (which super charges your late game, and can save you an immense amount of turns for a scientific victory) or Kilwa Kisiwani (if you get good suzerainties, breaking the game right there and then). Requiring a desert tile does not help either, as I'm often not able to locate a desert early on when I do want to build it (and when the extra charge helps the most). Make no mistake though, it's a good wonder, but I'm not going out of my way to locate a desert tile just to get it, if it means not foregoing a more lucrative settling spot elsewhere. It's just not THAT good. If I start with a desert tile (or my next 2-3 early cities naturally get a desert and some choppable forests), sure, but otherwise, no.
Forbidden City 
Kilwa Kisiwani 
Mausoleum at Halicarnassus