As a huge fan of Omni Magazine, I can't put into words how happy this makes me. I rarely see back issues at used bookstores anymore so this is a fantastic treat even if the scans aren't that great. (Okay, "aren't that great" should read "nearly dismal.") Nonetheless, there are different formats including epubs and Kindle files.
A "Best Of" edition edited by Ben Bova and Don Myrus. Sorry, my scanner's on the blink.
More info from the site, via Wikipedia:
In its early run, OMNI published a number of stories that have become genre classics, such as Orson Scott Card's "Unaccompanied Sonata", William Gibson's "Burning Chrome" and "Johnny Mnemonic", Harlan Ellison's novella "Mefisto in Onyx", and George R. R. Martin's "Sandkings". The magazine also published original sf/f by William S. Burroughs, Joyce Carol Oates, Jonathan Carroll, T. Coraghessan Boyle, and other mainstream writers. The magazine excerpted Stephen King's novel Firestarter, and featured a short story, "The End of the Whole Mess". OMNI also brought the works of numerous painters to the attention of a large audience, such as H. R. Giger, De Es Schwertberger and Rallé. In the early 1980s, popular fiction stories from OMNI were reprinted in "The Best of OMNI Science Fiction" series and featured art by space artists like Robert McCall.