http://coingen.bluematt.me/status.html
Gamecoin, Cloudcoin, Doubloon, Onecoin, and Americancoin have definitely been generated by coingen.
If there've been multiple coins by those names, then certainly the fact that at least one of them was a coingen coin is an important part of the history, and may be one of the reasons why it's dead. And honestly it doesn't matter which of them was the original; this thread is only about which one is dead.
I'm not convinced this list is a very reliable indicator that a coin is dead. Bitcoin is currently on the coingen list between cybercoin and jean!
cybercoin
Waiting for 6 confirmations of 0.11 BTC sent to 1NRXAaUPRU4H8CLLxemtGvJzmiMNmn9H27
Not Started
bitcoin
Waiting for 6 confirmations of 0.16 BTC sent to 1PkmJs49MmEUrBiBBy1VsYehZsE94c5j3C
Not Started
jean
Waiting for 6 confirmations of 0.01 BTC sent to 1CSdhjKLDNYoCidRG15CuW3oadRoRSGKs8