Takoren said:
Kinda the latter. I often feel a bit out of the loop as there are many "big books" of the genre that I have yet to read and I want to be able to at least talk about them like I know whereof I speak. I actually liked The Wheel of Time (despite being very aware of its flaws), so that's why I've read that series, but for a while I had this idea that I need to finish any series I start, unless I literally hated it from the get-go. That's why I kept reading until I was midway through Soul of the Fire in Goodkind's series, and finally couldn't take it anymore.
Well, most of them are "big books" because they were popular. There are too many of them to get to. (For instance, I only ended up getting around to reading The Man in the High Castle a few years ago.) So if you check out the big one that is usually the first one in a series and it's a no go for you, it would make perhaps more sense to stop and move on to the next "big book" rather than try to keep reading through a series that isn't working for you and is slowing you down on your reading list. There isn't going to be a geek exam, and fantasy series can go on for decades.
It's hard to know just how revered the Thomas Covenant books are. I know that Donaldson gets listed along with Brooks and Kay as writers who helped birth the fantasy boom of the 70's and 80's (and now I've done it; I've unthinkingly uttered an incantation that will summon KatG to tell me that there was never a fantasy boom in either the 70's or 80's, as fantasy had always sold quite well even before then).
There was a huge fantasy expansion in the 1980's, all sectors, which I've told you before.

It started in the late 1970's. The growth of fantasy in the 1970's, while an extension of the 1960's and the paperback market in general, was fueled more by the 1960's authors -- LeGuin, McKillip, Moorcock, Norton, LOTR, etc. By the time we got to the 1980's, it was a free for all -- Donaldson, Brooks, Feist and Janny Wurts, Terri Windling, Charles de Lint, Emma Bull, Stephen Brust, Tim Powers, John Crowley, David Eddings, Zelazny, C.J. Cherryh, Pratchett, Piers Anthony, Jo Clayton, Barbara Hambly, Tom Holt, R.A. MacAvoy, MZB, Clive Barker, Stephen King, Dean Koontz, Robert McCammon, James Blaylock, K.W. Jeter, Peter Ackroyd, Robert Asprin, Diana Wynne Jones, Colin Dann, Jonathan Carroll, Tanith Lee, Laurence Watt-Evans, Jack Vance, Robert Holdstock, Angela Carter, Octavia Butler, Isobelle Carmody, Gene Wolfe, Orson Scott Card, Anne Rice, Brian Jacques, J.G. Ballard, Diane Duane, Terry Bisson, Patricia Wrede, Lisa Tuttle, etc. Plus all the sixties and seventies authors still publishing most of them. And the Japanese stuff that started to come in. And the tie-in novels and the Conan reboots, some of which were written by Robert Jordan. If you concentrated on just the 1980's books, that would probably be too big a pile to get through.
Donaldson's Thomas Covenant series was seminal and one of the biggest selling around -- it sold more than Shannara at the time, and pushed Donaldson into phenom territory, though not quite to that level. The second book in the series, however, was the best-selling novel of the entire year, all types of fiction, in the U.S. and the series traveled fairly well globally. It was widely known in general fiction. It was also seen as a dark, gritty, edgy series that was an anti-Tolkien, as it had a grumpy, misanthropic, suicidal middle-aged leper as its protagonist, who thinks he's hallucinating and does some bad things. It was seen as being a bit of an acid trip fantasy coming out of the seventies and a nod to Joseph Conrad and Faulkner. It was a continuation of stuff that fantasy writers were doing in the 1970's, but it played very well in the 1980's. When Donaldson did Mordant's Need, that was a shift to less dark fantasy, but also were big bestsellers.
But very few fantasy authors are "revered" and those are usually quite older authors like Lovecraft, Tolkien and White. And even the "revered" ones you don't have to like. If you made everybody love the "big" fantasy books, then fans would not have nearly enough to argue about. It's that lots of fans are in deep disagreement about them that helps in part to keep them seen as big or historic in the field.