Stanley J. Weyman, Under the Red Robe (1894) - intelligent swashbuckling.
Leslie Charteris, Enter the Saint (1930) - three very entertaining novellas.
Edgar Rice Burroughs, Jungle Girl (1933), not a lady Tarzan but a fine lost civilisation tale.
Perley Poore Sheehan, The Red Road to Shamballah (1933), a great pulpy adventure story.
Edison Marshall, Dian of the Lost Land (1935), a fine lost world tale.
John P. Marquand, Thank You, Mr Moto (1936), an unusual spy thriller
Berkeley Gray, Miss Dynamite (1939), an outrageous and immensely enjoyable thriller.
Manning Coles, Drink to Yesterday (1940), a thoughtful and rather dark Great War spy tale.
John Wyndham, The Midwich Cuckoos (1957), chiling alien invasion story.
Alistair MacLean, The Dark Crusader (1961), a superbly crafted adrenaline-rush thriller.
And of these ten which would be my pick as the best book I read in 2015? I think I'd have to go for Berkeley Gray's Miss Dynamite - so much fun in one book.