E. E. "Doc" Smith

I just like his books, especially the Lensman and Skylark series, although I also have a soft spot for The Galaxy Primes. Yes it is horribly dated, and terribly overdone, but he is still "a blinding flash and a deafening report."

The Lensman Series

There is a net faq available for the Lensman series. Links to the Lens is another source of Lensman related information.

Triplanetary

First Lensman

Galactic Patrol

Gray Lensman

Second Stage Lensman

Children of the Lens

Masters of the Vortex

The Skylark Series

This is the story of a Washington, D. C. chemist, and the adventures that ensue his discovery of a strange metal that serves as a catalyst in the conversion of copper to energy, and his harnessing his discovery as a space drive.

The Skylark of Space

Skylark

Skylark Three

Skylark of Valeron

Skylark DuQuesne

The Family d'Alembert Series

This series of ten books, co-authored by Stephen Goldin, details the exploits of Wombat and Perriwinkle, the two top agents of an Imperial Secret Service, who also happen to be circus people carrying on a family tradition of espionage and aerial artistry.

Since Smith himself really only wrote portions of the first book and left a very brief outline of the remainder of the first book, this series is regarded with disdain by many. It has been a while since I read them, but I thought they were, in the main, fun mind-candy space opera, although I really disliked the resolution to the series in the final book or two.