I love reading, probably a little too much to be objective in this sort of thread. But here’s a few opinions anyways, by genre:
Fantasy: For some fun, easy, light stuff, try the five books in The Belgariad, by Eddings. There are a lot of reasons to trash him (he’s absolutely mailing his latest series in, he does the same general cliches a lot, and I’m sure a lot of other issues), but his first series is… well, light, easy, and fun fantasy, especially if you haven’t experienced him before (since you’re not sick of him doing, well, the same thing in every book/series he writes).
A step up gets you to Raymond Feist, particularly his Riftwar and Serpentwar stuff (Magician is where to start). Again, pretty by-the-book fantasy for the most part, but very enjoyable page turners. Quality varies outside those two series - he has an entire “making more money out of characters and ideas I already have lying around” trilogy - but his latest stuff is pretty good again.
Science Fiction: For cyperpunk, I second the Neuromancer and Snow Crash recommendations made by Derleth. It’s not usually a genre I end up loving, but both those books are great. Another author I recommend whenever I get the chance is C.S. Friedman - pretty much anything she has written (she’s done, um, seven books between fantasy and sci-fi), but The Madness Season is a standalone and probably my favorite.
More Traditional Fiction: The Count of Monte Cristo is definitely more readable in a shorter translation… the one I have is just a pretty generic book of similar brand to the ones you’d get in HS for “classics”. A Tale of Two Cities is by far my favorite Dickens, though that’s almost certainly pushing too close to “stuff I hated in HS”.
Niche Non-Fiction: I’m not a big non-fiction fan in general. If you have any particular passions, though, there’s probably a great non-fiction book out there that you’ll love. We always do the sports threads, but frankly I can’t think of a “must-read” football book, though there are certainly some good ones out there. Battle Cry of Freedom and A Brief History of Time have near-permanent places at the front of my bookshelf, but unless you’re into civil war history or theoretical physics, respectively, prolly not your thing. Rob Neyer’s books are good stathead baseball stuff.
Crazy Fantasy Assignment: Read everything Margaret Weis and Tracy Hickman have ever written, and write a thesis paper about how the quality can vary so widely from “young writers finding their style” to “brilliant and enjoyable fantasy” to “mailing it in for the paycheck on a series that was finished a decade ago”. Okay, so that might be a little too homework-y!
People like me are sort of bad for this question, though… because I will read anything that’s even mediocre within fantasy or sci-fi, plus anything that’s of high quality in any other genre. It gives me something to do between sporting events other than work and sleep.