Satsuma (Citrus reticulata), also known as Mandarin or Tangerine. All three words are interchangeable. There are several (many) cultivars of Satsuma, including Owari, Kimbough, and Early St. Anne just to name a few. There are taste differences, but the major difference is time of ripening. As a class, most Satsumas ripen before Thanksgiving. Believe it or not, some of the best quality eating is before the peel even turns orange. Of course they can be eaten when they turn, but if you start to see the least little tint of color, give it a try. If you don't like the flavor, wait a couple of days and try again. This works well if you have lots of fruit, if you don't, wait until they give you color. As your tree gets bigger, and you have more fruit, you will develop an eye for when they are perfect. Fruit do not hold well on the tree, they become large and puffy very quickly once reaching maturity.
One of the big selling points is they peel very easy, also being known as "kid glove" and "zipperskinned". This makes them great for kids.
Satsuma is considered the most cold hardy of commercial citrus, 18 degrees is pretty much it's lowest limit for short periods of time. Get down to 15 degrees and you can expect some pretty significant damage.
As for suggestions on the best variety, it will all be a matter of taste. I have and grow a bunch of different kinds. Owari probably being my favorite. It is very sweet. If you like a little bit more on the sour side, Keraji Mandarin is very good. There are many places online to find satsumas, with a little perseverance you can locate some of the harder to find cultivars.
Just to give you some food for thought, Juanita Tangerine came to be as a chance seedling from a grocery store tangerine. It was planted by a Juanita Barrineau of Barrineau, South Carolina. This tree actually survived 0 degrees in 1985. I mention this to encourage you to try planting any seeds you get in the fruit you are eating. Who knows, you might end up having the next great cultivar!