I just thought I'd reply with hearty agreements all around. Demon, I'm thrilled to see what an amazing impact Brandon's books have had on your life. Sometimes it's just amazing.
Since NBGA has yet to make an appearance, I also thought I'd make a few remarks on George R.R. Martin's A Song of Ice and Fire series--remarks which could probably be applied to a couple of the other suggestions made throughout this post. Granted, Insomnius, I'm not Bookstore Guy, though he and I have had this conversation before . . . but I might be able to make some suggestions as to why he suggested the series.
First, I'm impressed you set the series aside. Not because of the series, but because of the genre. It says a lot. It says that you know what you like, and I'm always thrilled to find other readers like that. Readers don't have to suffer through crap we don't like . . . Hell, Tolkien and Lewis wrote their works because they couldn't find anything they wanted out there (granted, Tolkien wanted a LOT, but we're grateful for it.) So I'm in your camp there. It doesn't surprise me that it was Martin either . . . people either love him or hate him.
That said, you should know that Bookstore Guy didn't suggest Martin because of the language, whether it's vulgarity or its anachronisities . . . though I have to confess: they aren't that anachronistic. Most of the profanity has been around since about the 1400's . . . heck, the OED has a reference for SOB that dates back to 1330. Granted that doesn't exactly mean that these words were common place back then, but they DID exist and there are recorded uses. Since Martin has based much of the setting of ASoIF on the War of the Roses, which started in the mid-1400's, the language isn't exactly out of place . . . though the profanity is probably used more in Martin's series than it would have been back then. I say you've got a good point though in this: no reader should have to put up with distractions. If it distracts you, then it's not your type of book.
Your second point can definately be applied to Martin . . . He's got a cast of thousands, and there is a lot about his world he just doesn't reveal. It makes many of the events in the books seem very coincidental, or convenient, or inconsistent. That section where Catelyn Stark returns from the grave as undead made me drop the book. I hadn't had any preparation for that. Part of me loves it, and part of me doesn't. However, just because something hasn't happened in the series doesn't mean that it can't. Returning from the dead isn't exactly an unfamiliar occurance in fantasy . . . and let's face it: we had no warning that Gandalf would come back. We just sort of take it for granted (decades after the book was first released) that this is how the book needed to be. All that we know is that Eru (God) sent him back . . . Similarly, there are many things in Jordan's Wheel of Time which we are told are impossible, but managed to be overcome. I remember thinking certain characters were done for after they were stilled or gentled . . . it had been clear that not even in the Age of Legend had that been curable. Convenient that the characters find out how to do it here.
This, however, is more of a direct address to why BookstoreGuy suggested Martin . . . and why the series is so loved and hated. It is different in many ways. Much of the fantasy liguistical aspects are pretty plain and straight forward; much of the relationships and situations are basic (bastard son of the king, people seeking the crown, dragons, etc.); and the characters, the thousands of characters, don't stand out as uniquely as they do in most fantasies. What people love is how these elements combine in unexpected ways. It's the fact that there really IS no congruity. *SPOILERS BEWARE* Our "hero" dies at the end of book, a boy is left seriously crippled, the best swordsman's HAND is cut off (why no bad guys ever thought of that before, i DON'T know), and we've only seen people come back to life with BAD effects. *END OF SPOILERS* It's unexpected, and instead of the thrill of anticipating a foretold event, we anticipate an explanation. The characters may not stand out (there's no elf, no dwarf--wait. Scratch that last one.), but that's because they aren't as cookie cutter as we expect them to be. It takes more investment, but we enjoy characters because their choices describe them, not their quirks. It's a harsh way of writing, and it's risky. Just about as many foibles in Martin's style as there are fortes . . . it isn't for everyone. Hell, it isn't for MOST people. But others should be made aware that it is there.
As for your final point, I must concede here. Martin is VERY quiet about how these religions work. I personally wish there were more information about that. It's a very fine line between ambiuity and TMI, and I personally think you're on the ball here. He's ambiguous, and I'm not sure if the value of religion will ever be clarified in the series. The War of the Roses was a very gritty, harsh thing. Religion can be incredibly impotent concerning the matter of succession. That seems to be what Martin's series is about . . . an issue of struggle. Not of Good versus Evil, but struggle between people in general. My feeling is that if a religion has power, then it should have a purpose for that power (reasons behind it, and goals before it) . . . but then again, I'm not choosing how the book is written. Just whether I read it.
Hopefully you can see that BookstoreGuy recommended the series, not because it was perfect or for everyone, but just that it has a strong track record. He and I both find issue with some aspects of Martin's writing . . . but mostly were just damn jealous, and just wish we could write that well and have so few issues ourselves.
Merit-wise in general, however. I'm not going to touch that one. The world itself could argue about what stories have merit and which don't, and the discussion would last until the end of time. Merit is one thing to one person, and another to the next. Martin just so happens to fall into the category of authors for whom there isn't much middle ground. Either way, Excellent points, and I'm interested in hearing what alternatives to Martin you might recommend.
EDIT: Other than Gaiman. He's fabulous, but I've read just about all that he's done.