You Thought Demigod Was The Only One?
CoH - Couldn't play till first patch (on mp)
EaW - Connections were just as bad as Demigods if not worst. Took them a while to patch, Stardock however are fixing it now.
Half-Life 2 - It was a disaster. Nobody could play it forweeks because everyone had to activate through the then newSteam. It was a complete nightmare.
Hellgate London - Not much needs to be said..
Anarachy Online
Age of Conan - Balance was horrible...Healer class apparently had higher dps then other classes
Diablo II - Sold 10x as much as they expected, servers overloaded
CnC3 - Not even on release date, but later on. Servers kept going down and you couldnt log in.
Vangaurd
Demigod is not the only one. Give it a week or so and give them a chance to redeem themselves before we really start flaming these guys. Lets not forget how nicely balanced this game is for one just released. From what I've seen these guys have given better support than any company has for a game so far and are really working their asses off to get the game fixed.
Note: Add any more games that have had sucky release days here