you are asking a very sensitive question here.

there is no definite answer, and there are fans for each coin which are easily offended by these topics.

all I can give you, is my list and rationale.

 Bitcoin is the leader
 Litecoin is top contender, I think it will trade closer to bitcoin.
 Dogecoin appears real enough, amazing community partication. How I wish they merged mine with litecoin (which they turned down.) Has Potential.
 Peer/Name these are all mined together by the same group of people, they lack individuality this moment.
 Quark pretends to be a good coin, but it is premined and all mined out. Not sure how they plan to distribute effectively.
 Primecoin had a good idea, but lacked follow through, if only it was marketted by professionals.
 Feathercoin is a left over from history. With a dev team that no long do anything innovative at all.
 Zetacoin is all mined out, they wait for that before pumping, so I do not trust it. a get rich scheme for someone.
 Vertcoin is also driven by pumps, without pumps it was dropping every single day, they are also based on non-required scrypt-N.
 Darkcoin has some great and interesting features, I think there's innovation advantage, there's a reason it has been holding well. has potential.
 Worldcoin is fast coin by a good dev team with business sense and Chinese buyers. Has also been holding well like Darkcoin. has potential.
 Infinitecoin started to drop uncontrollable last week, lost over 50% already. Though they released a road map trying to savage themselves.
 Novacoin is listed on BTC-e and has good supporters, though trading volume is considered too low.
 Megacoin started a tumble downwards, like Digitalcoin before it. I think that's it for them. I like their community, but there's just nothing left.
 Most country based coins are scamcoins, including Aurora if you ask me.
 Anycoin that's premined is a scamcoin to me.
 
my dream coin will be mix "Litecoin's Position and popularity, with Doge's community and hype, Dark's innovation/programmers, and World's Name, Speed and business sense".    So in short, I am saying I think the good coins are Lite/Doge/Dark/World

That being said, now here's what I think is not enough for each of the above:

Litecoin became so big, the dev team are afraid to make big changes.
Doge is too driven by the inner circle and community doesn't have much say. (some will disagree, but that's my call.)
Dark's innovation has good and bad sides to it, though I think they have the smartest computer nerds.
World's media attention is still too low and might hurt them should they don't catch on.