If you're thinking of teaching English abroad and wondering where you should teach then I'd also take some time to consider the location. Before you jump into any one place I'd suggest doing your research on the place and on the culture/country. Next you should decide whether you want to live in a big city or a small one. A big city in Asia can be nearly 20,000,000 people and what's considered a small city can still be a million or possibly more (especially in China).
First off as simple as it sounds, things are different abroad. Things that you take for granted will be absent. Conveniences and other foods that you enjoy will be absent.
Living in a big city
Food can be a big cultural doodad. Some people struggle with it. Many of the teachers that I interviewed found food to be one of the biggest challenges to living abroad. Living in a big city will enable you to buy more foods in the supermarket that you are familiar with. You'll also find a greater diversity of restaurants.
Other stuff that you'll tend to find more of in a big city:
- Books. If you think you might like to do some reading then living a big city will usually grant you more options as far as finding English books. Although more options isn't necessarily a lot of options.
- Social outlets. You'll find more of an array of bars, discos, clubs, martial arts, language centers, hiking and yachting clubs, and other social outlets.
- Clothes and products. Finding clothes that you like can be a challenge as can finding clothes that fit.
In short the bigger cities will be more cosmopolitan and international. You'll find more options ranging from anything from live music to English books. In a sense they are more comfortable, however they could have other factors that you may not enjoy, like: pollution, crowds and large populations. And even though there may be more options in Beijing than in Suzhou, don't expect to have access to everything like you do at home. Expect things to be different.
Living in a small city or rural environment
In smaller cities or more rural environments you'll have less options. You may still find fast food outlets (KFC, Pizza Hut, etc.), yet there will be fewer options. This will be a more cultural experience. I would only recommend this for those who are really open and very flexible.
All in all, big city or small, things will be different and you'll be in for a cultural experience. Having an open mind and being flexible is the greatest asset to having a successful experience teaching English abroad. You may also enjoy Troy Jodoin's interview in Korea where he talks about what kind of city would be good for you and also if you should share housing or get single housing.