Here are two annotated editions I stumbled across. I have collected a few Dracula editions, both in the original and in translations. The one book which never loses its facination for me.
Norton, 1997, edited by Nina Auerbach and David J. Skal
This one has 160 pages of essays and articles in small print. Reviews and Reaction is a nice idea, original reviews from the first publishing. There is an in-depth dissection of Dracula on the stage, written by David J.Skal, and more or less intellectual essays like The Occidental Tourist: Dracula and the Anxiety of Reverse Colonization by Stephen D. Arata.
Penguin, Plume, 1993, edited by Leonard Wolf
This has an informative introduction for rookies up to Anne Rice. Basically it is at times heavily footnoted. The appendices are the text of the short story Dracula's Guest, a filmography up to 1985 (which today seems lovely old-fashioned, but was quite hard work back then) and a bibliography.
It's not annotated, but this version is a real labour of love on the part of the editor. Stoker's novel, several essays, the whole lavishly illustrated with maps, vintage postcards, a soft porn model shoot & Co.
From the first, I set myself against "literature"; the story was the thing, and no amount of style could persuade me to select a story that lacked genuine, unadulterated horror. For those who wanted something high-brow there was plenty.