I never read Frankenstein, Dracula, or Dr Jekyl and Mr Hyde. But I am intimately familiar with their various adaptations and differences from source to adaptations. In general, I like the story concept behind Frankenstein the most. I actually think we got 2 really good adaptations of Frankenstein, via GDT, and Dracula, albeit in the form of Nosferatu but that itself was an adaptation of Dracula with various changes for legal purposes when it was originally made.
I may actually read them at some point though as kids grow older and I start picking some classic literature I want them to read.