The War of the Worlds
A seminal early example of Scientific Romance, it's also a (very) thinly disguised critique of nineteenth-century European imperialism. As such, it's a fascinating piece of history in itself. The style is very evocative, although occasionally rather stilted in that uptight, Victorian way. Stiff upper lips abound!
Like many of my generation, it was all Jeff Wayne's fault (Hi Jeff!) I think I first read the book in about 1981, in my early teens.
The whole worldwide catastrophe is seen from a deliberately parochial first-person perspective, so the actual invasion itself is merely the broad-stroke backdrop for the detail of one man's survival quest. This is the main reason that the story has been revisited so often; there is so much space for extrapolation and expansion. The Martians' Heat Ray weapon is probably the first "ray gun" ever imagined, so Wells gets the credit for predicting the laser 62 years early, as well as foreshadowing the horrors of the WWI trenches with the deadly "black smoke".