the three big anon coins (Darkcoin, Bytecoin, and Monero)
Actually there are four big anon coins. Darkcoin, Bytecoin, Monero, and XC. You forgot XC.
There are in fact five, I find it strange that people consistently forget the longest living anonymous coin, Anoncoin. Soon to be the first to sport zerocoin.
Actually, those 4 anon coins are not anon
There is first true anon coin, and the oldest, like Apraksin wrote, Anoncoin ANC
only 4.2m will be mined,
just watch the value soon when zerocoin will be ready
before that, you can read and learn about ANC on
https://wiki.anoncoin.net/Anoncoin_Wiki