I chose Pioneer, because I currently own one and am very happy. I believe that their mid-fi receivers are as good as what's out there, but others offer more high end pieces not to mention seperates. Therefore, my choice reflects the pretty narrow criteria I had for my most recent purchase - receiver less than 1 grand, beefy amp section, good specs, and bells and whistles that lean more toward movies without compromising sound quality.
However, if cost were no object and I were shopping again there is a very good chance I wouldn't stick with Pioneer.