Here's My Top 5:
1.
Chicago, Illinois - Sears Tower and the John Hancock Center seperated by skyscraper after skyscraper. It's a very wide skyline, yet still looks so dense with buildings. When I think of Chicago, I think of those two massive black skyscrapers - I remember seeing them in a book and always wanting to go to Chicago. The lake adds to the skyline, as does the park (Millenium park I think it's called?). Not to mention there is a bunch a new skyscrapers in the works for Chicago, including the proposed 115 story (tallest in the US) Chicago Spire.
2.
New York, New York - Before the World Trade Center was destroyed, it was the most impressive skyline in the world. They're gone now, but New York is still skyscraper central, and is home to two of the best looking buildings in the world - The Empire State Building and the Chrysler Building. The skyscrapers and bright lights of Manhattan are too good to drop out of the top two. When I think of skylines, I think of New York City.
3.
Singapore, Singapore - One of the coolest looking skylines in the world. I love the curved waterfront look with the buildings hugging the edge of the land. Every building looks perfectly placed and all are well designed. I love the light color of the buildings, looks quite futuristic in contract to a classic skyline like Chicago. It looks like a floating platform dotted with lit-up skyscrapers.
4.
Hong Kong, China - The only reason this skyline doesn't beat out Singapore and New York is because I'm not familiar with the staples of the skyline. When I see a picture of the Chrysler Building, I automatically think Manhattan and everything that comes with it. When I see a picture of the Sears Tower, I imagine the cold Chicago winter with the lakefront lit up by the bright lights of the Loop. Hong Kong is damn impressive and looks great, but the familarity isn't there for me.
5a. Auckland, New Zealand - This is my biased pick. I've never been out of the country, and big cities are one of my interests, so I was very happy when I finally got to see Auckland. Auckland is home to the massive SkyTower, which at 328 meters (taller than the Chrysler Building) dwarfs any other building in the area. If Auckland added a couple big time buldings here and there, it would really rank up there as it's surroundings are as good as any cities, eg. the hundreds of sail boats, water front, harbour bridge, etc.
5b. Seattle, Washington - I remember being at my cousins house one night, I must of been 10-11 years old, and walking into the lounge to see a movie called "Sleepless In Seattle" playing on TV. I took no notice of it until I saw a view of the Seattle skyline at night, and just started watching. I ended up watching the rest of the movie and don't remember a thing about it except that Seattle looks amazing. Everything is perfectly placed, with the Space Needle right there in the middle infront of a backdrop of massive skyscrapers. Arguably the best looking city come nightfall.
EDIT: Indy, I've researched Chicago pretty extensively since it's one of the places I would want to live if I ever got work in the US. Just out of curiosity, which area do you live in?