Junkcoin: 1st random block (though can be pre-calculated)
Luckycoin: improved random block computation by using previous block hash, so can not pre-calculated unless the previous block hash found. Also luckycoin added accelerated diff adjusting to limit instamine
Diamond: 1st Pow/Pos coin with random blocks.
and,
Infinitecoin: fast fair distribution of large amount of coins, a lot more fair and decentralized as compared to Ripple.