http://bytecoin.org/
Darkcoin currently holds the top position - it's well developed, has a strong community and a good daily trading volume.
Bytecoin is the challenger - again well developed, strong community (though not on BCT) and is not a clone of any previous coin.
They both have fast blocks, however Bytecoin has a much larger total supply and Cryptonote 2 is in the pipeline.
It will be interesting to see how the competition between these two develops.
Darkcoin is an unstable instamined shitcoin that relies on unproven CoinShuffle shell games and risky Ponziesque Masternodes. Let's hear no more about it!
When did Monero "collapse?" I didn't notice. And OMG, have you seen how pushy the XMR bid wall is today?
Cryptonote is already on ver 2.0 (kind of like Leonard Part 6, but with less icky Bill Cosby).
I made the same mistake so smooth corrected me: