Asheron's Call 2. I used to play Asheron's Call, which was a decent game, involved much thinking and a good amount of micromanagement. I loved that game.
So one day I catch sight of AC2. It's the sequel, so it must be better, right? Wrong. The producers made a graphically amazing game, but damn near made it for 5 year olds, instead of adults. The playing mechanics were childish and easy, so was fighting, in and out of PK.
It should have been a clue to me that AC2 was trying to give away 2 week trials, and that AC2 never once achieved the subscriptions that AC ever did, even when AC was 4 years old at the time of AC2's release.