This year I've enjoyed two relatively forgotten science fiction classics thanks to HiLoBooks' new Radium Age Science Fiction Series. Launched back in May with Jack London's The Scarlet Plague, the series features science fiction of the early 20th century published during that fabled interregnum between early SF works by Shelley, Wells and Verne and the pulp boom of the 1930s. Radium Age SF was written by some pretty important literary figures, including London, Arthur Conan Doyle and Rudyard Kipling.
I've thus far read the aforementioned Plague and Arthur Conan Doyle's The Poison Belt, his second Professor Challenger novel. I've just started H. Rider Haggard's When the World Shook, and I look forward to discovering more of his invigorating brand of adventure. I haven't seen the second book in the series, Kipling's With the Night Mail, at any brick-and-mortar bookstores yet despite months of trying, so I guess I'll pick that one up online.
Most (if not all) of the books in this series have fallen into the public domain and can thus be read online, but I still have a fondness for physical media so I'm very pleased to see these century-old works back in print. Many of the titles feature illuminating forewords and afterwords to put the novels in their historical context.