What's EverQuest's secret?
 

It's got an unparalleled community, it's quite simply the best damn MMO out there. But why?

What made EverQuest so special for you?

The fear of death.

I was 12 and it was better than runedscape.

I was 16 and it was better than sex.

Three excellent reasons if I do say so myself.
Oh undoubtedly, though to give Runescape some credit. It's a really good free MMORPG, and back when I played it religiously, it was a much harder game.
With challenging gameplay, comes intelligent players. With intelligent players comes strong, friendly communities.

I never played classic myself. When I began the game PoP was already out, perhaps even LDoN. Even then I fell in love with it...and then was forced to quit when DoD came out and I realized SOE had turned the game into WoW.

But what I've learned about classic, Verant-era EQ has amazed me. This game is absolutely amazing for several reasons:

1. If you act like a jackass, or are even careless or inattentive for a small period of time, the game is likely to kill you. This tends to filter out stupid, incompetent people as the game repeatedly kills and frustrates them. Not only that, but dying is VERY significant (classic hybrid penalty, case in point).

2. This game doesn't treat you like a child. It doesn't spoon feed you quests or the next location for grinding even. It feels like the big, scary, open world that a fantasy MMO should. It makes you explore. It makes you communicate with people.

3. The Grind! It doesn't feel like a grind oftentimes. Yes, there is some tedium involved in leveling, I'll admit. But it doesn't feel as though the main objective is to reach cap as soon as possible and begin endgame. The leveling experience is something rewarding in and of itself, forcing you to explore and meet people(see #2). It's not straightforward or self-explanatory, and it's not just a means to an end.

I'm sure there's more reasons, but that's all I've got atm.

the dark elf bazooms

I started playing EQ back in the Luclin days I had never really messed with any other games out at the time (UO,Asherons Call) I remember coming over to an old buddys house and watching him chill in freeport on his uber gaming pc with voodoo graphics card (16mb) I believe. EQ has really good lore and it just draws people in, it doesent hold you hand and its challenging and fun. Challenge is something thats diminishing in newer games today no new innovation. Star Wars is a pretty good comparision for EQ. It was just at the right place at the right time and it was a hit for many reasons.

Half-Elves are much nicer.

EQ was so successful for many reasons, mostly, as pointed out by Brad McQuaid in his blog, because it was just timed right. It was a VERY good offering in an otherwise new genre (the 1st person immersive MMO).
Not to downplay its' qualities in their own rights, but it wasn't so much that it was amazingly good, it was just amazingly different.

I equate EQ to my first love. She may not have been a great girlfriend, but she'll always be the first. And for that, I'll always remember her fondly.