In some indefinable way the black face thus flashed upon me shocked me profoundly. It was a singularly deformed one. The facial part projected, forming something dimly suggestive of a muzzle, and the huge half-open mouth showed as big white teeth as I had ever seen in a human mouth. His eyes were blood-shot at the edges, with scarcely a rim of white round the hazel pupils. There was a curious glow of excitement in his face.Dr Moreau is one of the earliest mad scientists in sf history, and possibly the first to experiment on living creatures via surgery (Frankenstein's subjects are dead, at least when he starts working on them). It's one of Wells' early huge successes, published in 1896, the year after The Time Machine and the year before The War of the Worlds. The plot is rather basic - protagonist is shipwrecked, and ends up on an island where Dr Moreau is engaging in horrendous experiments to instill humanity into animals; it all goes wrong, Moreau is killed by his creations, and only the narrator escapes to tell us (and, scarred by the experience, he ends up fearing his neighbours in a passage reminiscent of Gulliver after the Houyhnhnms). It's short and taut; the central point is laid on pretty thick, but not for very long; the thrust of the story is a critique of the idea that science will inevitably improve life for us all (and if anything it is Moreau, the villain, who is identified with imperialism). You can get it here.
This was both my top unread book acquired last year and my top unread sf book. Next on those lists are Dark Matter by Blake Crouch and, stretching a point, Politically Correct Bedtime Stories by James Finn Garner.