People rarely regret buying an Accord. The #1 thing to check is whether you find the seats comfortable; quite a few people discover that Honda seats don't work for them after buying one. Aside from the seats and perhaps road noise, the main thing against the Accord is they depreciate more slowly than competitors, so you'll have to get an older one for a given amount of money.
Those who consider the Accord also often consider the Toyota Camry. The Camry is quite bland, but is reliable and comfortable.
For the model years you're considering, I'd advise the Chevrolet Malibu over the Chevrolet Impala, which was quite dated until it was redesigned (very nicely) for 2014. Unfortunately, we don't have much reliability information on either model.
The Ford Fusion tends to be nearly as reliable as the Accord, with the possible exception of the 2010 (one common problem with these is being addressed through a recall and could become a thing of the past).
Finally, many people like the Hyundai Sonata and Kia Optima. The 2011s are the least reliable of these, but even these are fairly reliable.
Have you driven any of these contenders? If so, what did you like and dislike about them?