Litecoin uses a slightly different algorithm, scrypt, as opposed to bitcoin’s SHA-256. Scrypt hashing is a memory intensive process, so asics for scrypt mining should be much slower to evolve than their SHA-256 counterparts. Bitcoin prices are moving in a direction that will make them difficult for the everyday consumer to swallow. Litecoin, on the other hand is still hovering somewhere around $10, this makes prices easier for consumers to conceptualize and thus makes it “better” money.
Namecoin stands on different merit. Most Namecoins are created through a process called Merged Mining which allows bitcoin miners to earn some extra revenue, without any appreciable increase in costs. Namecoin’s value has more to do with it’s long term potential to replace traditional DNS systems than as it’s viability as a currency.