It would be a stretch to say that Skyrim didn't offer a lot of content. How interesting that content is varies greatly from player to player, but there was plenty to choose from while exploring the world. With that in mind, it's not surprising that the initial DLC took so long to release. Dawnguard hit first on the Xbox 360, and it is packed full of content.
Dawnguard is best thought of as a whole new quest chain along the same lines as the Companions or the Dark Brotherhood with some additional features. Players will first hear about the Dawnguard from guards around the world as they mention how this band is fighting the newly arisen vampire menace. With little more than this information and a friendly, new quest marker, I went off to find these fearless warriors. Upon arriving at Fort Dawnguard, I met with their leader and was promptly put to work investigating Dimhollow Crypt, a place where the vampires appeared to be seeking something. After exploring through this new area and slaughtering a few vampires, I found myself faced with a puzzle, which I quickly solved, but things then became a little more complicated.
During the process of working through the puzzle, I'd been stabbed through the hand and infected with vampirism, but I had also found something even more interesting than a hidden artifact. I'd found Serana, a deceptively youthful-looking vampire girl who had apparently been locked inside the crypt for centuries. She was also carrying an Elder Scroll.
Serana seemed genuine, so I kindly offered to return her home to her father's castle. One fast travel later and I was walking into the home of the vampires. Upon meeting us, Serana's father seemed much more interested in the Elder Scroll than he did seeing his daughter after all these years, but regardless he offered to reward me for my troubles. At this point, I was offered the ability to become a vampire lord. If I turned him down, I would be forced to leave the castle and never be allowed to return. With that proposition before me, I turned my back on the Dawnguard and embraced my new vampiric powers. Hopefully, this wouldn't be a decision I would come to regret.
Thankfully, becoming a vampire lord was no hindrance and actually offered a few interesting new abilities such as being able to feed off humans, control certain NPCs, and summon various creatures. There are a host of other perks and abilities available to those who choose this path, even the ability to transform into a swarm of bats in order to teleport a short distance away. These features add an interesting dynamic, but are completely optional. Most of the time I remained in human form, choosing to follow the vampire path mostly for the story. The vampire lord form was simply too clunky in the forced third-person view for me to enjoy controlling it, as I much prefer to play Skyrim from the first-person perspective. So despite my personal preference to rarely change from human form, I still found the options robust and unique.
What really pulls Dawnguard along, however, is its story. Serana is a great character with a lot of depth and true motivation to be a part of what's going on. While most of the DLC's quests will have you doing many of the same things you did during Skyrim, the reasons behind why you're doing them are engaging enough to help drive the story forward. There are some unique areas to explore in this expansion, including a rather out-of-this-world locale that even offers its own set of side quests.
Dawnguard also offers legendary dragon fights for those who are high enough level, not that my level 30 character was close enough to the supposed level 50 requirement to encounter them. Perhaps they offer a new experience to some, but the few videos I watched of these fights didn't seem to differ too greatly from most other dragon encounters in the game. I imagine the loot might have been much better though, because there were few other items of interest to be found during the story portions.
Upon completing the entirety of the vampire questline, I restarted and chose to side with the Dawnguard. While the perspective was different to start with, it quickly fell back into the same path that I had taken during my first playthrough. After I started having to repeat content, I decided that I'd seen enough and went back to the main game to finish up quests that I'd left undone my first time through.
My recommendation of Dawnguard boils down to what you enjoy most about Skyrim. If you like exploring, completing quests, and working through the game's narrative, then it doesn't get much better than this. It's not likely to convert many of the game's dissenters, but fans should have more than enough to play around with. I spent nearly ten hours with the new content and found it immensely enjoyable, so for me it was well worth the wait. Since it was spaced just far enough away from the initial release, I was in the mood for more Skyrim and Dawnguard fit the bill perfectly.