I think the USA would probably win as well. Despite some unpopular actions it’s taken, it has name recognition going for it. It’s like the New York Yankees. There are definitely people who hate them, but they still have the most fans.
If we’re basing popularity on the number of people immigrating to a country, or wishing to, maybe Afghanistan is the most popular 
From that link, Net Migration Rates of some Western countries:
Canada: 5.96 per 1,000 population
Ireland: 4.99
New Zealand: 4.05
Switzerland: 4.05
Australia: 3.98
United States: 3.41
Netherlands: 2.91
Denmark: 2.48
For the record, my vote, in accordance with the OP’s rules, would be for the United Kingdom, specifically Scotland.
Usram, I’m not basing popularity on numbers, although I could if necessary.
You know, we are really asking the wrong people if we want an answer to the OP: (Bolding mine)
Most of us are reasonably happy with the country that we live in; we don’t have a need to go somewhere else to make a better life for ourselves. We need to remember that are billions of people in the world have no access to computers, or the Internet, and would much rather spend $15 on six months worth of food than a one year subscription to the SDMB.
And I think that quite a few of those people would vote for the USA. As **Marley23 ** said, we’ve got name recognition going for us. Is the US really a better place to emigrate to than Canada, or Sweden, or Australia? Probably not, all things considered. But the US has a reputation for being “the land of opportunity”, home of “the American Dream”, and all that.
So I think the US would win. Now if we take the OP’s option of adding +1 or -1 to our votes, that might sway the results things a bit. There are quite a few people out there that Really Don’t Like Us. But I’d bet a nickel that the USA would still eke out a win.
I vote for Costa Rica. The entire country is essentially a peaceful open air zoo.
Israel is 51. Dunno about 52.
Actually, atom bombs *have * gone off there: the Poms used to test them in the outback in the 50’s - pretty uncool, especially if you happened to be an Aborigine.
As I’m disqualified for voting for NZ {unlike that shameless hussy calm kiwi}, I’m going for Thailand: best food, fantastic beaches, and the people are so cool - laidback, funny and kind. Where else in the world can you get wolf-whistles from a pair of middle-aged cleaning ladies at the airport, who dissolve into fits of raucous giggles when you turn around and blow them a kiss? Oh, and if Heaven has beach-bars, they will be like the ones in Bo Phut.
The Netherlands.
Belize, maybe?
I dunno, there’s a lot of folks who dislike China and I’m thinking the Middle East, only able to vote on one hated country might choose Israel first.
Oooops sorry! I didn’t read the rules correctly evidently.
My ammended vote goes to Britain. Just cause I loved every moment I was there (2 years) and the people are brilliant. Plus they have all us ex-colonialists to vote for them. 
The US. The kid who everybody knows and fears always wins the popularity contest no matter how much everybody hates him. In fact, I think the fact he is hated probibly helps his popularity. Its true, think back to the people who were popular at your high school.
I was planning on voting Ireland or New Zealand when I clicked on the thread, however, RYBTP’s convincing argument has persuaded me. Djibouti it is!
Let me be the one to support the downtrodden masses of Andorra.