It's fascinating to watch this kind of discussion crop up again and again...and it always manages to miss the topic, in my opinion.
If you look back at the posts in these discussions, most people's fond memories come from the vivid campaign worlds that were available for the respective editions. Well, there are a lot of campaign worlds available for 3E that are just as vivid and stimulating for the imagination as the "old" ones. Some are revamped settings from older editions, some are pretty much original, some take old ideas and recycle them...but most of them are sparkling with ideas, and damn hard to resist.
If it's just about the rules, I'd say no ruleset really "stands the test of time", for the simple reason that rules, in their basic form, are simply a tool that is used to simulate actions in the respective setting. Some people swear by the tools they used 25 years ago to do it, some prefer the fresh and constantly updated tools from a few years ago. The same can be said about the old Atari games, for example. Some people prefer to use the good old machine they used 25 years ago to play the games, others prefer to run an emulator on their spanking new Win XP machine. What matters are the games themselves.
What is different, in my opinion, is the marketing strategy. I'm of ambivalent opinions regarding the fact that, with D&D 3E, the rules and the game's athmosphere have been separated. It has it's advantages and disadvantages, and I don't want this to creep into this thread, as it has been discussed to death already, but at the moment, and that's from the impression I'm getting personally, it seems all you need is the 3 core books to start a decent game.
Which isn't the case, at least for somebody who's coming fresh into this game, without roleplaying experience under his belt, who may have, or have not, played a few computer roleplaying games or trading card games, or simply loves the LoTR movies. Because all he gets is a set of rules. Good rules, concise rules, and streamlined to provide minimum problems of usage (okay, I'm idealistic here...so let me

). My impression is that he doesn't get told to at least take a look at the FRCS or Eberron CS books to get a glimpse of what D&D is really capable of (or Midnight, or Scarred Lands, or Iron Kingdoms, et...). I mean, I don't know about the 3.5 core rules, but the 3.0 books didn't even have ads for the adventures WoTC published for 3E back then? There's an ad for Dragon Magazine in the DM's Guide, hurray

. And yes, I know that a good RPG/hobby store will tell the new roleplayer that there are a lot of adventures, too, that you can start your fun with. But where's that at WalMart, or other big stores where you simply buy the book without "assistance"?
That's my main gripe with the "new" strategy 3E brought up.