That I've personally experienced...Age of Conan.

To start, they had a cap on the amount of players they were going to let in to early access but didn't tell anyone that until the access to early access was "Sold Out." As I recall, you also had to pay part of your game's cost ($5 worth) up front with the incentive, which they claimed was to help with the bandwidth costs of downloading the game.

Once it began, there was constant game-wide lag that made it completely unplayable for stretches at a time, many players learned just how poorly optimized the game was even on decent (at the time) computers, and disconnects were common. Bugs were even more common. Talents didn't work, gear provided next to no benefit if the stats worked at all. Those that made it through the disconnects and lag learned that the first level 20s full of voice acting and plenty of quests were unlike the next 60 - the VA dropped off immediately and there were large stretches of grinding between available quests (when they worked).

And the cherry on top of that time frame? The 3 days of EA, which people actually had to pay some of their game cost up front for and was "sold out" ended up going down for about a day and a half.

And then launch proper began, and more and more issues came to light, including the hilarious one where building Tier 3 cities with your guild were a literal impossibility - you needed more items in one person's inventory than you could actually have in one person's inventory, and you needed a Tier 3 city to gain access to the PvP siege system, one of the hyped features of the game.

I think there's only a few that have worse launches, and it's certainly the worst I've personally experienced.