The only incarnation of the Realms I absolutely love is the classic 1e grey box. Maybe a few of the 1e/2e FR series for zooming in on some areas, but not all of them, and arguably you're better off without some... The setting is lean, concise, and actually leaves vast stretches of the wilderness completely open to the DM to do what they will. And the areas that are described are mostly thumbnail sketches for the DM to use as inspiration when building their own Realms. The promise of the unknown and adventure was everywhere - a lot like the 1e Greyhawk boxed set, but a little more fleshed-out.
2e's and especially 3e's releases wrecked the Realms for me with canon bloat. Too many novels, too many supplements, and just altogether too much going on. Those blank spaces got filled in. Those thumbnail sketches turned into 8 megapixel photos. The sense of wonder and mystery was harmed.
I didn't care much for the 4e setting until the Neverwinter book came out last year. That's actually a remarkably well-done setting that finally gives you some hint of what this spellplague business would be like, and finally show what's potentially cool about it. With that said, it's no Grey Box, but it's a workable setting with some good stuff going for it.
-O