Omni magazine was a great influence on my love of science and technology in the 80s. I was thrilled to find out about this.
The Internet Archive has a near-complete run of Omni, free for download or viewing online. Even if you’ve already read the articles or fiction elsewhere, that means you can see it in the original format, complete with gorgeous illustrations or amusingly dated New Yorker-style cartoons. The Best of Omni collections in the set are a good place to start; if you’d like a better idea of what you’re getting with each issue, check out the separate Complete Omni Index.