Trickster Online, rip
There was just something about the game that kept me entertained for a really long time and made me come back to it after quitting for so many times. The private server was fun for a while but still there was something lacking.
And friends i found in Trickster are the people who i’ve been gaming with for over seven years :3
Grand Chase season 2
Good ol’ season 2 ;_;
Need for Speed World 
Gunshine 
It was shutdown on the 30th of November in 2012. It looks really bad now that I look at it again lol. Honestly, I didn’t like the game at first but the community was really, really nice to me and as I continued playing it, I enjoyed it so much. It’s too bad that they never brought it back.
#Equestrian Mario Cart with lolis
http://aliciaonheart.weebly.com/uploads/1/3/8/3/13834981/1429569474.png
Infinity Online (the one by Windysoft)
Neo Steam Online
Luna Online
Ragnarok (died for me with Renewal update, also they recently closed official servers in my region due to lack of players)
There are bunch of others that gone bad either with some ‘big’ update or by publishers’ monetization.
Peria Chronicles the other mmorpg i was hype for if IMC failed my expectations has no new news since 1945. I’ll pretty much considering it dead.
Animu Sandbox action mmorpg with heavy pet raising mechanics…who isnt sold for that!
is it still alive?
GunZ 1 was able to make its name due to pro kstylers making fancy moves that made people interested in the game. boy i thought i was gonna get carpal syndrome from that keyboard smashing fingers.
GunZ 2, devs made a game for casuals and not their true fans the kstylers. they should have kept the kstyle mechanics even though those were originally complex glitch moves but it was what popularize the game from other shooters.
I would try that.The pets aren’t the cutest but I like the character design.
If i play Peria Chronicles ill probably raise the ugliest looking pet 
Gunz The Duel
Survival Project
Endless Online
Emil Chronicle Online. One of the few MMOs that I really love.
RIP Gunslinger Stratos
http://steparu.com/latest-news/1975-gunslinger-stratos-reloaded-shutting-down-march-29th
Gunslinger stratos wasn’t that fun when I played it, the aiming mechanics were pretty odd for a shooter mobs, but it was cool.
“pRO” Philippine ragnarok 
Just Closed down last year 
Soulmaster
Forever lost in the void of gamigo’s website
It’s been 5 damn years.
Oh, and Dragon Gem, the dinosaur of side-scrollers.
Lots of games on here that I never knew shut down; makes me kinda sad.
R2: Reign of Revolution
I really lost my old r2…
Random note:
Most of the counted online games are from Japan…
Pretty ironic that Japanese games seemed to be more charming but not very long lasting at the same time… or should I say sad? As jrpg fan I usually stick with Japanese games to a degree, I’m checking the origin of a game before even building an opinion on it. It’s lame I know, but for all the stuff out there, I need limitations.
RO and now ToS are an exception, probably because of how it changed my life early on. I’m kinda emotionally attached huh.
Star Wars Attack Squadron… so much potential was wasted by incompetence
City of Heroes is the first to come to mind.