To watch Amazon Instant videos–whether they’re the free movies or TV shows you get with your Amazon Prime account or one’s you pay for–you’ve got to have either a TV that’s already compatible with the way Amazon delivers their instant (over-the-Internet) videos, or you’ve got to have a compatible device to add on to your TV.

As of September 2011, there is a huge list of devices compatible with Amazon Instant videos, including:

Once you’ve got a viewing device compatible with Amazon Instant Video, you just need to register the device on Amazon’s website. For specific compatible model information–or to register your device–visit Amazon’s page for compatible streaming video devices on their website. Most notably missing from the list is the Sony PS3. This is pretty disappointing, considering how many families–mine, included–use their PS3s to stream Internet content; hopefully, Amazon will fix this oversight in the near future.

Paying Amazon Prime members–in other words, members not on a free trial, nor Amazon Mom members who are receiving Amazon Prime shipping benefits free of charge–have access  to thousands of streaming movies and TV show episodes completely free of charge. Some of Amazon’s most popular free videos include every season of every Star Trek series, including Original Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise.

Personally, I love that Amazon is offering the additional benefit of free streaming movies and TV to Amazon Prime members–though the best Prime benefit of all is still the free 2-day shipping. But even for Amazon customers who aren’t Prime members yet, having the freedom to stream movies and TV programs right to their TVs is pretty awesome.  It beats making a trip to the local video store–if you happen to still have one in your neighborhood–and the selection can be a lot better than you’ll find in brick-and-mortar retailers.