Bitcoin, Namecoin, PPCoin, Devcoin, Terracoin, Ixcoin, Freicoin
Other than namecoin and Devcoin none of those support merged mining.
Technically Bitcoin doesn't support merged mining but as long as the dependent coin supports it Bitcoin hashes can be used even though Bitcoin is "merge mining ignorant". From the Bitcoin network's perspective the Bitcoin blocks are hashed as "normal" it just happens that sometimes those blocks (above or below the difficulty target) can be used to solve other chains. Bitcoin is unaware that the blocks are being used for other purposes.