The Elder Scrolls Skyrim Heartfire DLC 1: This DLC gives the option of making your dream house. But only in 3 locations over Skyrim. Building your house cost a lot of money, time. The end of the day is very helpful. Something dislikes you can't custom the items, house, as well as people and creatures attack your house from time to time.  

The Elder Scrolls Skyrim Dawnguard DLC 2: This DLC main focus is about being a Master Vampire or Vampire Hunter. The best thing about the DLC is Crossbow that is a very powerful weapon, being a vampire master rather than a normal vampire. On side-note, the DLC adds new locations, new characters. Most interesting things about this DLC found-out what happen to When a soul is trapped in a Black Soul Gem, found-out about the backstory of Falmer. 

The Elder Scrolls Skyrim Dragonborn DLC 3: This DLC place on the island of Solstheim rather than in the country of Skyrim. Bethesda Studios deserved credit for using something other than Skyrim. Similar to Fallout 3 DLC's, and Fallout New Vegas takes place in a new location with new characters, new weapons, etc. The focus of this DLC is about someone called: Mirrak has brainwashed the residents of the Island. The plot-twisted that Mirrak is Dragonborn as well.
This DLC reminds me of Shining Ises from The Elder Scrolls Oblivion. The reason because of both place on an Island. Both have there own new content and take place in a location not see at all or not much of.