<span class="bold">SubSpace</span> One of the first online action games, and one of the early adopters of the term "massively multiplayer," although back in '97 that meant 100-200 players. 2D spaceships fighting in enormous mazes with few set goals and a beautifully balanced set of powerups and specials. Mostly forgotten now, but you can still play it in an (imho) abridged for. When Virgin Interactive folded they allowed the players to reverse engineer server software and it's been going ever since.
It's mostly traditional CTF these days, but the greatness of the game as originally designed was the freedom factor. People would claim territory just for the fun of it, disrupt the flag game in the most obnoxious way they could think of, hunt the people disrupting the flag game, or just sneak around looking for ways to become despised.
<span class="bold">The 7th Saga</span> My favorite SNES game, and I think maybe the best of them except for Metroid 3. It was called Elnard in Japan, an Enix release from the Actraiser / Soul Blazer era. This was a top-down RPG with 3D(ish) over-the-shoulder fights. The music had a sweet ambient electronic sound which was rare back then, the bosses were fierce, and even the random trash could be very difficult. Encounter the wrong set of them while traveling what you thought was realtively safe country and you were in trouble! It's pretty desolate if you look at it now, but for me the overworld just felt much bigger than the other RPGs of the time, maybe because it was so damned difficult to travel.
Most importantly, the game had 7 playable characters. You would choose one at the beginning, and of the 6 you did not pick, one could become your sidekick while the others would compete against you to find all the runes which were the game's ultimate goal. Most of these would remain friendly or neutral towards you, but some were hostile and others would become hostile toward you depending on events. Even your sidekick might stab you in the back and take your runes if you weren't careful.
The runes would grant you extraordinary powers while you held them. Teleportation, free combat buffs, that sort of thing. I remember my excitement and trepidation as I approached a new town and saw it glimmering on the overworld radar, indicating a rune was present. Was it buried in a dungeon beneath the town, or was one of my fellow travelers there, having beat me to one of the runes? Would he challenging me for the ones I had managed to find?
Adding to the high stakes of these encounters was the fact that you couldn't die. If you were defeated, you found yourself back at the inn. "It would have been too late if we had waited longer," the inkeeper would explain. If your defeat was by one of those other 6 adventurers, you would wake up to find your runes looted and the advantages they'd provided gone!
<span class="bold">Anarchy Online</span> Flash forward to present day - or to 2001 if you prefer - and to my favorite game. Or at least my favorite you can still play. AO is the only major MMO from the pre-Eve / pre-WoW era which is still in good health and can be played more or less as it was originally designed. Quite well known when it came out, it was soon forgotten because its launch was a disaster and the developer alienated many of its original population during its first couple of years.
Today it is still in good health, and it's because Funcom has mostly turned it over to the players - that is to say, it has hired from the player base to such an extent that, according to the current game director, everyone now working on it was drawn from the player population. It shows. The newbie areas aren't abandoned like they are in most old MMOs, old dungeons are still well-traveled, and the PvP and crafting systems encourage creation and level locking of alts which means you seldom have to play alone. The free play flavor includes everything prior to the expansions, and doesn't cordon freebie players off in their own subculture as is usually the case. Most of my friends and guildmates in this game are on free accounts.
What's really special about AO, apart from its unique atmosphere and art style, is the skill system. There are very few hard level restrictions on abilities or equipment. Instead, wear requirements involve skill levels, which can be raised by investing the points you're awarded each level, but also by raising the base abilities they derive from. This includes buffs, which are not only cast but also granted by permanent or temporary implants as well as equipment. A considerable portion of the game is spent trying to "fit into" armor, weapons, implants, or the computers used to run these buffs (lol nanotech), often using one to meet temporarily the requirements of the other. This can be complex and rewarding in itself, but more interestingly it means players are constantly interacting with each other during downtime, and I mean with everyone - not just guildmates in your level range.
My favorite thing about AO has always been the music. It's played dynamically from 5-15 second clips which blend together so seamlessly I didn't realize it was happening for over a year. The mood changes depending on your location, the time of day, that sort of thing. Which would mean nothing were it not very, very pretty. Added to this is an extraordinary background ambience of distant alien sounds which blend in to really make the setting feel like another world in a far-off time.