Quick call Greenpeace! Arthur sure likes Giant Squids, doesn’t he.
And the greatest line ever spoken in truth by a character: “Here I sit waiting for an atomic bomb to go off under my ass”.
If the OP can excuse just a little Godlike Aliens with Clarke-level technology (mainly at the ends of each book), two books I really enjoyed were The Sky People and In the Courts of the Crimson Kings, by S. M. Stirling. They’re a shoutout to the Edgar Rice Burroughs versions of Venus and Mars, based on the premise that aliens long ago terraformed Venus and Mars and transplanted Terran life there. So we have a Venus with dinosaurs, prehistoric mammals and cavemen and a Mars with a forty-thousand year old imperial civilization based on biotech.
Nipples!
Kind of a guilty pleasure read, but if you enjoy lots of explodey action, David Webers Honor Harrington series is pretty good. Its not classic sci fi, but it does get exciting, and his descriptions of the battles and general technology of the universe are very well thought out. No AIs, magic, psychics. Just lots and lots and lots of nuclear explosives and lasers heading across space.
You can read it here(Site is legit. there are many books there freely available from the publisher).
Ok, so it doesn’t tackle any heavy issues, but its still fun. Like an action movie in book form. 
Another one I enjoyed, about a post singularity world, is Accelerando. A trip to the stars in a spaceship the size of a soda can? Can do!
What, no love for Bruce Sterling, The Best Idea Man in SF[sup]TM[/sup]?
His Islands in the Net is the best near-future extrapolation I have ever read, and I’ve read quite a few. Sterling is not just a god SF writer, he’s a good writer. For example, his characters have family arguments that are just like family arguments I’ve been in.
For the OP, I can also recommend The Difference Engine (Best. Alternate. History. Premise. EV-AH! And not just because it nearly happened.), Heavy Weather, and The Zenith Angle.
Sterling’s non-fiction is great also. For the OP, I’d suggest The Hacker Crackdown - one of two books on computer security everyone should read, IMO. (The other is Cliff Stoll’s The Cuckoo’s Egg.)
I would classify treecats’ telempathic ability as “psychic”, myself. And of course it also has FTL, which is probably a lot less realistic than telepathy, anyway.
That’s a good question for the OP, actually: Is faster-than-light travel acceptable? Because that eliminates a heck of a lot of science fiction, and if you can suspend your disbelief around it, it opens up a lot of possibilities.
I would say that faster-than-light travel is acceptable as long as it is based on some sort of physical machine and not “these people have mental powers that allow them to send space ships through FTL travel”.
If it helps, Honor Harrington is Horatio Hornblower in space.
Ah, so there’s no point in relating how I found Ben Bova’s writing to be a bit poor from a literary point of view?
It just felt like everyone in his books turns up and plays their part. No tension or sense of wonder, they’re almost as much spectators to the story as I the reader.
And FTL Travel
And materials with fantastical properties
And teleportation
And stasis
hun, go to webscriptions, Baen has a free library of some 150-200 free ebooks by many of the best authors in SF/fantasy. You can read the whole book, and if you go to their webscriptions page, they sell books either as singles or in bundles. You can read sample chapters and decide if you like the book enough to buy it.
I heartily recommend Elizabeth Moon - her Harris Serrano series is pure space Horatio Hornblower, as is David Drake’s Honor Harrington. Lois McMaster Bujold also writes the VorKosigan series, which is also space SF though she also does write 2 fantasy series as well but those involve ‘magic’ so you may not like them, though I think you should at least give them a try [Curse of Chalion is one of my favorite books ever] John Ringo writes military SF, alien invaders attacking earth [one of his military units has a very large tank equivalent named Bun-Bun, after a giant fictional rabbit] Murray Leinster writes golden age SF, pulp =) fantastic and A Logic Named Joe is free on webscriptions free library. Pournelle, Niven and Sterling wrote the Co-Dominion series, Mote in Gods Eye was recommended above, but it is part of a series of books.
Really, Baen is IMHO one of the foremost publishing houses of high quality SF and Fantasy in the business. They sell NON-DRM ebooks in multiple formats, and you can download them in any and all formats, repeatedly. They are very reasonable in cost [usually about $5US each] and you can read sample chapters.
Yeah, I thought about that, but they have such a minor role in the books its hardly worth mentioning.
I just wanted to point out that while Bun-bun has a giant ego, he is not actually a giant rabbit. He is a regular sized lop-ear with a switchblade. Except when he has a pistol, or grenades, or a rocket launcher, or millions of dollars, whichever is handy.
My tastes in SF sound very much like the OPs. With that, here are some books I’ve really enjoyed:
Rendezvous With Rama by Arthur C. Clarke.
Spin by Robert Charles Wilson (Axis, the sequel is already out, but not as good IMHO, and there will be a third and final book in the series).
The Accidential Time Machine by Joe Haldeman.
God yes, great book.
Even better (for the OP’s stated fields of interest): Tomorrow Now: Envisioning the Next 50 Years.
Hm. I always thought that was Captain Kirk.
Easy mistake, Kirk spends so much time blowing his own horn. 
There’s far too much out there…
Depends what you consider “too much suspension of disbelief” (or just glossed over). WOuld FTL or time travel fall into that category, or just the psychic powers and impregnable shield and superpowers stuff?
My favorites over the last umpteen years:
Andre Norton (yes, she once wrote real science fiction, if you can find it) Time Traders, Catseye, Galactic Derelict, Starman’s Son; then she started to write more “weird” stuff like Judgement on Janus
Robert Heinlein - most of his early stuff, up to Moon Is a Harsh Mistress; then he discovered he could write soft-core stuff about strong, sexy women who loved to screw, and all his books seem the same. But do read - Early Heinlein novels
Rocket Ship Galileo, 1947 *
Beyond This Horizon, 1948 (initially serialized in 1942, and at that time credited to Anson MacDonald)
Space Cadet, 1948 *
Red Planet, 1949 *
Sixth Column, 1949 (initially serialized in 1941, and at that time credited to Anson MacDonald) (aka: The Day After Tomorrow)
Farmer in the Sky, 1950 (Retro Hugo Award, 1951) *
Between Planets, 1951 *
The Puppet Masters, 1951 (re-published posthumously with excisions restored, 1990)
The Rolling Stones, 1952 (aka: Space Family Stone) *
Starman Jones, 1953 *
The Star Beast, 1954 *
Tunnel in the Sky, 1955 *
Double Star, 1956 – Hugo Award, 1956 [2]
Time for the Stars, 1956 *
Citizen of the Galaxy, 1957 *
The Door into Summer, 1957
Have Space Suit—Will Travel, 1958—Hugo Award nominee, 1959 [3] *
Methuselah’s Children, 1958 (originally a serialized short story in 1941)
Starship Troopers, 1959 – Hugo Award, 1960 [4]
[edit] Middle Heinlein novels
Stranger in a Strange Land, 1961 – Hugo Award, 1962 [5], (republished at the original greater length in 1991)
Podkayne of Mars, 1963 *
Orphans of the Sky, 1963 (fix-up novel of two connected short stories, both originally published in 1941)
Glory Road, 1963—Hugo Award nominee, 1964 [6]
Farnham’s Freehold, 1965
The Moon Is a Harsh Mistress, 1966 – Hugo Award, 1967 [7]
I Will Fear No Evil, 1970
Asimov - All his early stuff -
The Robot series:
The Caves of Steel (1954), ISBN 0-553-29340-0 (first Elijah Baley SF-crime novel)
The Naked Sun (1957), ISBN 0-553-29339-7 (second Elijah Baley SF-crime novel)
The Robots of Dawn (1983), ISBN 0-553-29949-2 (third Elijah Baley SF-crime novel)
Robots and Empire (1985) ISBN 978-0-586-06200-5 (sequel to the Elijah Baley trilogy)
Galactic Empire series:
Pebble in the Sky (1950), ISBN 0-553-29342-7
The Stars, Like Dust (1951), ISBN 0-553-29343-5
The Currents of Space (1952), ISBN 0-553-29341-9
Original Foundation trilogy:
Foundation (1951), ISBN 0-553-29335-4
Foundation and Empire (1952), ISBN 0-553-29337-0
Second Foundation (1953), ISBN 0-553-29336-2
Niven and Pournelle - Most of Nivens known space stuff - a bit smarmy, but a good read. The one I would recommend is “A Gift From Earth”; with Pournelle there’s “The Mote In GOd’s Eye” and sequel “The Gripping Hand”; the Janissaries series; Pournelle alone wrote “A Spaceship for King David”
I once made it a point to read as many Jack Vance novels as I could; some are pure fanatsy, like Dying Earth, but most are plain space opera - the Demon Princes, the Alastor series, The Grey Price, To Live Forever, Big Planet, Lamplight, Lurulu, Planet of Adventure (Tschai, 4 books)…
CJ Cherryh for some good REALISTIC science fiction - Several known universe Alliance series, including Downbelow Station, Cyteen trilogy, Chanur series, and the triple trilogy (plus a tenth one, due in paperback May 4th) the Atevi series: Inheritor, Conspirator, etc. She has a fantasy series too, the Fortress Series and the Exiles Gate series, so if that’s not your cuppa tea, skip them.
Vernor Vinge - anything, there’s not a lot; A Deepness in the Sky is really good, so is A Fire Upon the Deep; The peace war and Marooned in Realtime have “bobbles” (stasis bubbles) but otherwise are good hard science.
Lois McMaster Bujold - the Miles Vorkosigan series. She has now transmuted into magic/fantasy, so read the cover blurbs before you buy.
Arthur C. Clarke - much of his early work and the Rama series.
Actually, browse any list of “great scince fiction” and you will probably find most of them are gems.