Star Wars Galaxies, Played it first after the infamous NGE update but I loved it, Played the Jump to Lightspeed expansion, Kashyyyk expansion and then Trials of Obi Wan expansion, My guild and I on Starsider, SinisteR, Ran all the "dungeons" from IG88, Tusken King, Imperial Star Destroyer etc...
We also held base busting on Friday nights for all guilds so everyone could get GCW i.e Galactic Civil War points, Through these points you attained ranks and through ranks you could buy some very cool looking stuff through the Imperial/Rebel vendors, Of course you could go to the PvP planet Restuss and just cross an invisible line by the spaceport, Get flagged for PvP and go kick some ass in open world PvP but base busting was a good way for people not into PvP to get ranks.
Space itself was also immensely fun, Go to a star port, Go to a terminal, Select your ship and you'd load in above the planet, Equip various player crafted parts that you could buy on the market boards like better shields, Better engines, Better weapons etc... lots of other stuff too on the marketplace from housing items, Armour so on and so on.
And all the ships, Minus the smaller ones, You could get up off your seat and wander around them, Even decorate them if you wished, Join the Imperial, Rebel or Neutral pilot factions, Get more ships, Uniforms, Badges/achievements, Some of the biggest ships you got through special actions, Like the Imperial Decimator or YE-9, HUGE ships that you could have a lot of your friends on.
Also had a Mustafarian bunker, Player housing was very popular, That I put on the planet Lok, Kind of like Tatooine in looks, Decorated it to the gills with tens of Billions of credits worth of rare items that I obtained over the years, Looked amazing, There was even a little music box, Kind of like jukebox, That you could set to continuously play music inside your home, I permanently had "Star Wars - Funeral Suite" playing quietly when you walked in, Gave a very sad atmosphere but went with the galactic civil war era the game was set in.
But then things started going wrong with the people who ran it, Sony Online Entertainment, Developers were being laid off, Really loopy decisions being made, Planned game updates were put on hold, Servers began getting more and more unstable, This is all with a fairly healthy monthly subscription player base, But then news came of Star Wars The Old Republic and it all made sense, SWG had to go to make room for SWTOR as those in charge didn't want 2 x different Star Wars MMO's, SWTOR in my honest opinion apart from the voice acting and story telling is a far inferior game and the community is rancid.