Machu Picchu - I'd still rather capture this one than build it. Primarily because the AI will usually get started on it before I can and at that stage of the game, if I don't have a mountain in the first ring I'd likely have to buy the mountain tile to be able to build it.
I still missed the part where "best Wonder" = "Wonder you most want to build". If anything it's a point in Macchu Picchu's favour that unlike, say, the Oracle, or oftentimes Petra, you
can capture it and get its full bonus. If it's a Wonder you want enough to actively attempt to capture it - potentially a greater investment than just building the thing - it seems perverse to cite that as a reason for downvoting it.
Chichen Itza 24
Hanging Gardens 30
Leaning Tower of Pisa 27
Machu Picchu 18
Neuschwanstein Castle 11
Notre Dame 26
Oracle 16
Petra 21
Porcelain Tower 15
A lot's changed since I was here last, it seems. I see two here I don't feel deserve to make the top tier - ND and CI. So Chichen Itza gets my downvote (experience has taught me that downvoting the Castle is a wasted vote...). Seems odd that so many people downvote Wonders purely because the AI typically gets them first, yet Chichen Itza hasn't suffered that hate.
Up with Petra once again, since it seems to be getting more downvotes either than Macchu Picchu or Hanging Gardens (the latter being the Wonder I consider deserves to win overall), although the Oracle looks in serious need of help - it's not the lowest-ranked yet, but it's going down faster than the other surviving Wonders.
While all good Wonders are situational, Petra is less so than is being emphasised here - most sites where you want to build it are good production cities, and it can quite reliably be built in a second city if you have a suitable area. Good desert terrain is in any case common in my experience. While you won't want it if you have only one or two desert tiles, you don't need or necessarily want an all-desert city to make it valuable, and with workable city radii being so broad, there's a very good chance of finding a site with some good desert resources/hills to exploit using it. Moreover building it anywhere gives a valuable Engineer point and a 'free' Terracotta Army once you get Archaeology. If you settle specifically for Petra and beeline Currency, you can reliably get it on Immortal before the AI, which seems not to prioritise it particularly even with desert starts. And as for its tech position (raised in an earlier post), Currency is a good go-to early tech for markets and the progression to Guilds for trading posts, even if for some reason the Civil Service path doesn't appeal.
And as ever the most important reason for voting for Petra is: because it's Petra.
EDIT: Amended to reflect votes cast while writing this.
I play SP and MP, but in my last 20+ random starts i never had capital which is good for Petra
20+ random starts...... and you say that Petra is not trivialising desert start, and is awesome wonder?
I doubt I've played 20 games since G&K hit, and I build Petra over half the time, I'd estimate, regardless of civ choice (that includes Denmark, incidentally, when I built it in my second city - which was ultimately probably the best production city I've ever had in a Civ V game). Usually in my capital, but often in my second city.
maybe its the civ choices for me lately, but ive had desert starts more than 50% of the time and that's not with Arabia, Egypt, or other desert-like civ as far as i know. I did get them with Ethiopia though and that was expected as they are more desert like.
I've got it with, at the very least, Siam, Songhai (that one reasonable), Denmark, Sweden and the Maya. And most of those have starting bias enabled.