I just finished reading Bram Stoker's original novel, Dracula, for the first time. I read some sort of kids' abridged version thirty years ago, but I quickly realized as I read that I didn't know squat about the story.
The first thing that struck me about it is how effectively suspenseful and atmospheric it is. I mean, it's SPOOKY! Vampires aside, it's a classic of the gothic tradition, especially the first section when Johnathan Harker is trapped in Dracula's castle. It makes excellent use of the setting, and the Transylvanian wilderness, the superstitious locals, and the creepy old castle really come to life.
The later section when Lucy is slowly being drained is excruciating and riveting. The endless succession of setbacks and minor victories had me constantly hoping she could be saved, but constantly fearing the worst. When Van Helsing breaks into her tomb and calmly discusses the necessity of cutting off her head, it made my skin crawl.
Overall I'd say Dracula stands up reasonably well for being more than a hundred years old. (I mean the book, not the dude, who also is in remarkably good shape despite his extreme age.) Certainly it's a bit dated, especially in its almost comical view of women. Some of the characterization is absurdly simplistic, and some of the prose gets a bit purple, but overall it wasn't a bad read at all.
I was surprised to find that Stoker's rules for vampires aren't the same as the general standard you see these days. Dracula could walk around in broad daylight, for instance. On the other hand, he had quite a long, arbitrary list of unexpected limitations. His invasion of London turned into a bizarre logistical exercise as he imported boxes of cursed Transylvanian dirt to which he had to return every day at dawn.
Another thing that struck me was how pervasive Christianity was in the story. I think atheism and skepticism would have been nearly-incomprehensible concepts to Stoker and his contemporaries. Christian faith permeates the book. When Stephen King revisited the topic of old-school vampires in 'Salem's Lot, he explained the impact of crucifixes and the like as deriving their power from the wielder's belief, not from God or Jesus directly. In Dracula, though, Christianity is utterly intrinsic to the story.
The epistolary structure of the novel - it's all diary entries, letters, and documents - felt a bit gimmicky to me, but it was fairly effective. It lets the author use first-person narration with all of the strengths of immediacy and close identification that it brings, while still telling the story from multiple points of view. There were problems. People wrote things in their journals that were cringingly personal, despite knowing that the others would be reading everything. Overall, though, the "diaries and letters" approach works reasonably well.
A big part of the plot hinges on a preposterous coincidence, that Johnathan Harker, the lawyer who encounters Dracula in Transylvania, is engaged to the best friend of the woman Dracula randomly selects as his first English victim, thus bringing all of Dracula's opponents together. I would say it's the novel's one significant structural flaw, and it's a humdinger, but on the other hand it's easy to ignore.
All in all I'd call Dracula far from perfect, but still solidly entertaining after all these years and well worth checking out if you haven't read it. There are annotated and illustrated versions out there, but you can get the basic novel from Amazon for free.