There are also coins like Premine (PMC) and NFD that were replaced by a new coin via an official swap. Premine was replaced by PreminePlus (PMP) and NFD was replaced by NeXT Horizon (NHZ) - later renamed Horizon (HZ). Last time I checked, the PMC network was completely dead while the PMP network was barely limping along. Not too sure about NFD.

Then there are also historical altcoins that have been abandoned too. The Tenebrix network is completely dead right now. I tried connecting the other day and couldn't find any nodes. Fairbrix was replaced by Litecoin but its network is still functioning - although only barely.

Lots of scam coins are dead too - e.g. Magnetz which saw the dev dump his coins after the ICO. Then you have coins like Stackcoin which probably never actually existed at all beyond doctored screenshots.

Lottoshares is dead. That one failed because of a bug which the dev couldn't fix. It even reached a multi-million dollar market cap at one point.

There are some others here as well:

http://bitcointalk.org/index.php?topic=588413

I will be Locking this thread till the 23rd of june '15.

COV was. It's value was 450k sat.

Xaurum is still being traded to my knowledge.

Etc...

There are quite a few examples to my knowledge.