Blackcoin is a fork of Peercoin
Vericoin is a fork of Blackcoin

Both of those are proof-of-stake coins, copied from the original Peercoin source code.

More coins (3%) isn't necessarily good. There was Netcoin for instance, that was 45% year interest. When you get too much interest, people sell them all and now Netcoin is worthless.

Peercoin is the original proof-of-stake coin written by the original programmer.