This isn't a series, but a set of fiction that I think fits the bill. Conveniently all of these works are available free online:

After Life: http://sifter.org/~simon/AfterLife Blindsight: http://www.rifters.com/real/Blindsight.htm Passages in the Void: http://localroger.com/

The Metamorphosis of Prime Intellect (from localroger.com) is also pretty good in the imagination expanding department but be forewarned: parts of it are very hard to read (quite gruesome).

Future History series - Heinlein

Known Space series - Niven

Uplift series - Brin

Dune series - Herbert

Mars trilogy - Robinson

Ian M. Banks "Culture" series.

"Matter" might be a good one to start with if you're looking for something similar to LotR.

Thanks. This is the series I have been looking for. I almost feel bad for not knowing this book existed.

I'm a fan of Charles Stross's Accelerando. It's epic to the point where it takes place across generations. It also has the nice benefits of being free online, and you'll occasionally see cstross post here.

Neil Stephenson's Anathem. Maybe not tons of actual space bits, but most of the rest of it matches what you want.

this is exactly what I want. thanks

The Foundation series.

Just got "Foundation" from the library today (because someone stole my Red Mars book :( )

Seconded.

Great story, characters, and writing.

William Gibson: Neuromancer, Count Zero, Mona Lisa Overdrive Orson Scott Card: Enders Game Neil Stephenson: Snowcrash Isaac Asimov: The Foundation (series)

I am not sure these qualify as space epics, but they are all good reads.

Ahhh, I've only ever read one SF series that left me with the same sense of wonder as the Lord of the Rings. You just have to try Hyperion/Fall of Hyperion, by Dan Simmons. At first I thought it was ridiculous space opera, with loads of jargon and technical impossibilities that just made it read like 3rd-rate SF. That is right up until the point where Simmons blindsighted me by making all of that stuff an absolutely necessary part of the story. I can be more explicit without giving out a few spoilers, but I've read a lot of SF, and this is really a cut above the rest.

I've read the first two (I thought the 1st book was better actually) - however I've heard the rest of the series is not so good.

Yeah, I wasn't as big a fan of Endymion - it was much more touchy-feely in its justifications than was the first series. Still enjoyable, but not in the same league as Hyperion.

Alastair Reynolds "Revelation Space" series is fantastic. He also writes some great stand alone pieces (House of Suns for example). He is also quite strict about being hard sci-fi (no faster than light travel for example).

Also The Culture series by Iain M. Banks is pretty amazing but tends to be multiple independent stories within the same universe. He is also much softer on the science (quite a lot How does it work? Quite well thank you descriptions).

"He is also quite strict about being hard sci-fi (no faster than light travel for example)."

Or rather, it was tried (in the Revelation Space series) but did not work out well...

The Night's Dawn trilogy by Peter F Hamilton will absolutely rock your world, going by what you are asking for. After this, go for The Commonwealth Saga by the same author. You really, really are missing out on a treat, but the best thing is that you have around 6,000 pages worth of epic space opera waiting for you in those books, and I envy the fact that you have all of them still to read - as quickly as you want!

I'd recommend the Great Three : Asimov, Clarke, Heinlein

Read Emphyrio by Jack Vance. It's just one book, but it's a fantasy book set in space. The main character is a woodcarver, but there are spaceships that travel to many inhabited worlds. Vance is one of the best authors I know to make a world feel worn, unlike the sci-fi of many other authors.

"A Fire Upon The Deep" by Vernor Vinge.

A Deepness in the Sky, which is loosely related to A Fire Upon the Deep, is also great and also won a Hugo award.

For epic science fiction with huge space battles, depth of story and interesting characters you cannot miss books by David Weber, especially the Honor Harrington series

thanks everyone. I have a few year's worth of great books to read. Thank God for HN.

thoughtful, accurate and spiritual? Sounds like battlefield earth to me.