For every best IT place to work and play there is also a worst, here's a look at where you should go...and where you shouldn't.\nWorst Cities to Work in IT: International Edition\nThe Worst U.S. Cities to Work in IT\n10 Best U.S. Cities for IT Jobs with Tech Startups\nThe Best Cities for Finding IT Jobs in 2012United States' Best: Silicon ValleyImage by City of CupertinoLet's start with the homefront. If you're a techie who wants to be in the center of the high-tech universe, there's only one place to be: Silicon Valley. It's the home to Apple, Google, Facebook, Oracle, Intel, and where venture capitalists along Sand Hill Road fuel great ideas. Oh, there's also a nice little city to the north called San Francisco.(Picture: Apple's planned "spaceship" campus in Cupertino, CA).United States' Worst: Middle of the Hatfield-McCoy FeudIf you watched the History Channel's recent "Hatfields & McCoys" miniseries starring Kevin Costner and Bill Paxton, you'll know that the Tug Fork off the Big Sandy River separating West Virginia and Kentucky isn't the safest place to be. You can get shot just for having the wrong name.Ireland's Best: DublinEarlier this year, Microsoft began investing an additional $130 million in its data center in Dublin. Computer training schools have also popped up. Dublin is fast becoming one of the most exciting tech pubs, errr, hubs. Great, now we're craving a pint of Guinness.Ireland's Worst: BelfastThe Belfast "Good Friday" agreement of 1998 ended the Troubles in Northern Ireland, yet there are still occasional outbreaks of violence. Most folks will tell you Belfast is perfectly safe, citing low crime rates and friendly people. Then again, Belfast is the birth place of the Titanic. How much bad luck can one place have?UAE's Best: Dubai Dubai is the world's richest dream destination rising out of the desert. You can venture onto a man-made island in the shape of a palm tree, snow ski in a hotel while the sun beats down outside, and work in some of the most modern facilities. We hear the nightlife is pretty exciting, too.Dubai's tech scene, Internet City, is the largest information and communication technology business park in the Middle East.UAE's Worst: DubaiThen there's the ugly side of Dubai. Despite its modern wonders, Dubai is steeped in cultural tradition. American expatriates can land in jail for all sorts of minor transgressions: kissing or holding hands in public, swearing or making rude gestures, driving with any amount of alcohol, wearing revealing clothing at places other than the beach, etc. Be careful, techies.England's Best: London Image by ForbeatenLondon's calling! This is the place to be if you're looking for tech work abroad. Check out London's major tech locale, Tech City\/Silicon Roundabout. "Despite our investors being in Silicon Valley, I came here because all of our customers have a strong presence in London," says American ex-pat Rob Fitzpatrick, founder of startup FounderCentric.England's Worst: NottinghamA few years ago, think tank Reform ranked Nottingham as the most crime-ridden major city in England and Wales. Apparently, the evil Sheriff of Nottingham got the last laugh on Robin Hood. Most recently, a dozen men and two youths were sentenced for rioting last summer, which included firebombing a police station. And you thought Sherwood Forest was dangerous.France's Best: Paris Image by PasaParis is one of the great cities in the world and should be on the short-list for job destinations. There is so much to do: spending leisure time in a cafe, gazing at the Eiffel Tower, touring the cathedral of Notre-Dame. Of course, we're not all that sure about the technology scene. Our guess is it's a bit insulated, given the many years France spent pushing its own version of the Internet, called Minitel.France's Worst: Rest of FranceQuick, name another major city in France you'd want to visit.China's Best: BeijingImage by stuck in Commons via flickrNo global list would be complete without a city in China, which is well on its way to becoming the country capital of the world. The tech capital in China is Beijing, home to a wealth of tech talent, venture capital and the acclaimed Tsinghua University. If Beijing isn't your thing, try Hong Kong. A couple of years ago, Forbes called Hong Kong China's next tech hub.China's Worst: LinfenImage by sheilaz413;flickrA few years ago, CIO.com put together a slideshow of the Worst Cities to Work in IT: International Edition. Guess what city topped the list? Answer: the coal-producing center of Linfen, China. Combine coal, air and people, and you get one of the most polluted cities in the world.Brazil's Best: Sao Paulo Image by ThinkstockSao Paulo is a city on high-tech's fast track, specifically the emerging area known as Brooklin. Who's in Sao Paulo? AT&T, Microsoft, Samsung, Oracle, Hewlett-Packard, to name a few. Sao Paulo's favorite tech son is Mike Krieger, co-founder of Instagram, the picture-sharing app that Facebook just bought for $1 billion.Brazil's Worst: Sao Paulo SlumsImage by Paul KedroskyYou don't have to venture far from the booming central city of Sao Paulo to find the worst places. Sao Paulo has some of the largest slum populations in South America. We're talking shanty towns made of cardboard and wood and the occasional concrete wall. It's a tale of two cities.Germany's Best: MunichImage by YukibaHere are some cool stats about Munich: It's the third largest city in Germany, plays host to many large companies (BMW, Siemens, Allianz) and has one of the largest communities of programmers. Even better, Munich has a buzzing nightlife and is well-known for its breweries and tasty white sausage.Germany's Worst: East Berlin in the '80sImage by SiyuWe're going back in time before President Ronald Reagan told Russian leader Mikhail Gorbachev to "tear down this wall." The Berlin Wall, built in 1961, became a symbol of communism. Living in East Berlin up until the late '80s was an oppressive, Orwellian experience. Thankfully they tore down that wall in '89.Australia's Best: SydneyImage by ThinkstockSydney and Melbourne are the two largest cities for IT in Australia. Actually, they're the only cities in Australia. (Just joking, mate!) We're going with Sydney because of its hot tech startup scene, venture capital, good bars, and lots of cool architecture. Check out Sydney's Super Digital Precinct. Sydney is to software what Melbourne is to bio-tech.Australia's Worst: Great Barrier ReefImage by ThinkstockThe Great Barrier Reef is a SCUBA diver's paradise\u00a0-- that is, until the man in the white suit shows up. When this happens, you don't want to be anywhere near the water. News reports of swimmers getting attacked by great white sharks in the Great Barrier Reef are becoming more common.Greece: Got Euros? Image by ThinkstockWe're kidding, of course.