What is the best LED television for people on a budget?

I am moving in with my best friend who only has an old, 42 inch television. We are looking for a flat screen tv, preferably LED, must be in the forty inch range and have 1080 resolution. I have found a few tvs like this in the four hundred dollar range, but I know nothing about tvs. What is the best tv fitting these parameters in the four hundred dollar range?