I recently sold my car as I no longer needed to drive to an office every day for my job. I have a very busy job that requires me to work a lot of hours, so dealing with putting up ads, answering phone calls and emails would have been a pain and I live in Manhattan, so setting up a test drive would have been a pain. Also, I was not getting another car, so going to a dealer was not going to happen either.
Adding all of this up, I went to Big Bucks Auto. These guys buy cars pretty much on the spot from people and are not creepy used car salesmen. They were all friendly and professional and work quickly. They ran the history on my car, did a physical inspection, went on a test drive and put an offer together. BAM! That was fast. They handle all the paperwork, they will even pay off your loan and deal with bank / financing company hassle for you. The whole process took an hour or so. They are also a few blocks from an E & F train station, so after you sell your car, you can easily get home.
Although they pay less than what you could get selling the car yourself on Craigslist or Ebay, it is way less hassle and if you are a very busy person, it is totally worth it.