In fact, Kista may be the perfect compromise for what you want: kind of a "small Silicon Valley", under an hour in the car to "big city", 30 mins to airport, and 30 mins to "totally desolate countryside". Be sure to bring warm clothes for winter, last time I visited, it was -10, you could see about 30 meters and there were 2 meters of snow in the street... which doesn't prevent the average Swede from driving 70-80 km/h.
Not over populated
Rules out China, Japan, and the entire EU with the exception of northern Sweden (outside The City), some now totally desolate parts of former East Germany, some rural areas in France and Spain, or other places in a land far, far away where you have no perspective whatsoever of finding a job, especially not in IT, and not well-paid either.
Sensible leaders and politics
That rules out planet Earth. On a more serious note, good governements don't exist. Human does not go with power.
France has a government that (from a German's perspective) does not look bad at all, though all French people I know seem to hate Sarkozy and disapprove of anything he does (no idea why, I've only seen him do things that are more good than evil in summary).
Germany maintains a dog and pony show run by clowns rather than a government. This circus comes with one half-baked new idea every two weeks (usually the opposite of two weeks ago). Plus, we do any Nazi idea that the USA come up with, but we do it first, and we do it right. Worried about SOPA? You must be kidding. Eavesdropping telephones and internet? Biometric surveillance? Hey, get down, we practically invented that stuff. It's for our safety and freedom.
Italy's government used to be somewhere in between Germany's pony show, Mussolini, and Mafia, but now that Berlusconi is finally gone, maybe things will get better. One can hope.
Now Belgium of course tops every other country in terms of government, having had no government at all for nearly 2 years because they could not agree on the election outcome. And guess what... the music played on.
Safe (both protected by the government and from the government)
Definitively not Germany. The police is good at criminalizing normal people, but if someone breaks into your house or your car, you never see police. If you're robbed or if there is a brawl, police takes 1-2 hours, because hey, getting into a brawl is dangerous. Better do some important park tickets first.
I do feel quite safe in France on both accounts, though I've heard much different from other people (admittedly, I stay far away from Paris, which is a different world). Rural France is where you leave your front door open and where cars stop when you cross the street.
Speaks English, since that's all I know
This will be a serious problem in most European countries (other than Ireland, UK, or Sweden... maybe 1-2 others). You might possibly find a job in a company that uses English internally as Hodgman said, but these companies are rare, and all in all it remains very problematic. In most EU countries, everybody hates the "stupid American who expects us to talk English". Seriously.
Forget about pulling that in Germany, France, Italy, or Spain (forget twice in France). Don't expect someone in the city hall or in an administrative office being able (or rather willing!) to talk English, and don't expect to get what you need. There is of course always the chance of being lucky and finding someone exceptionally kind and helpful, but I would not rely on these odds.
In Sweden, surprisingly, everybody in the street and in the shops speaks English and has no issues whatsoever with doing that and being just "normal" about it.
This, Sir, is so disqualifyingly wrong on all accounts that I can hardly find words to express.
Also, EU is dangerously close (a matter of days) to breaking up which will lead to civil disorder and socio-economic breakdown.
it's happening. The EU is finished.
There sure are non-deniable problems in 3-4 countries, and serious problems in one particular country. However, these problems are mostly home-made (with the help of two notable US companies) and have existed and been well-known for three decades, and the music played on. Kohl and Mitterand wanted the union at any price back then, and although everybody knew that Greece (and Italy, and some others) had forged their balance, this was silently accepted, because we wanted the union, end of story. Of course this has cost the union dearly, and it still does, but that's not something that was unforeseeable.
Also, it's not like Greece is really out of money. A few people get richer as money disappears, and a lot of people get a bit poorer, both in Greece and the rest of the EU. But again, that's not something sensational, new, or specific to Europe. The common people will have to work a bit harder, and they will be a bit less happy, but the music will play on.
The annoying thing about it is that as long as the union keeps doing everything to rescue a member country from collapse, at any cost (and it still looks like they will not back off any time soon) there is little incentive for anyone in the government to change anything substantially, other than maybe pro forma. An actual hard collapse would possibly be better both for the people in the country and the entire union.
As far as the UK go, they did not intend to be part of the EU or the Euro for the last 30 years, so that is not big news either. Who cares.