Here is a snapshot from Coinmarketcap from May 2013. This is to show how much has changed when it comes to altcoins only by looking at the top 10.

Bitcoin was always #1. But look at the other coins in the top 10. We have Litecoin. at#2. Fair enough, they are still around.

After that we have:
- Namecoin - down +80% since its ATH.
- PPCoin or Peercoin - down +85% since its ATH.
- Novacoin - dead or no liquidity.
- Devcoin - dead.
- Terracoin - down +96% since its ATH.
- Feathercoin - down +98% since its ATH.
- Freicoin - down +97% since its ATH.
- CHNCoin - dead.