Darkcoin is the clear market leader in anonymous-oriented coins, and is the oldest and furthest along in development. Per the Buffett rule that makes it the most attractive investment in this niche. As the the size of the niche, consider the following:
1. Companies dealing with crypto in their finances will not want competitors viewing all their transaction details. With Bitcoin (etc), every time an accounting dept. employee left Company A for Company B (or just wanted to sell secrets for cash), Company A's finances would be laid bare. So anonymity will be a Corporate Standard going forward - not some obscure niche for drug deals.
2. Likewise, don't assume governments will be hostile to anonymity. They can use it too. I can imagine some heated arguments right about now between NSA types wanting to ban it, while CIA managers across the table yell "NO!, we're using it to pay off informants and finance our operations in Whateveristan!" Who invented TOR, after all? Darkcoin is to money what TOR is to information transfer.
The same logic for #1 applies to just about everyone. Do you want your finances scrutinized by nosy neighbors? Sure, you can try to keep your accounts private, but I imagine there will be plenty of times that kind of info leaks out for a variety of reasons, and then you are exposed. So anonymity is for EVERYONE. We will all be wanting it. The only question now is how to most efficiently provide it. For now Darkcoin is the clear leader.
It might top out today. Or it might be the coin that displaces Bitcoin, assuming a couple things happen just right. All I know is that it is only at a fraction of its potential now, pumps notwithstanding.
Darkcoin is a BTC clone with gimmicks. No one with half a brain will be using this to move money from A to B through nodes ran on some guy's mother basement that happened to luck out with the linux instamine if his life depended on it. Anything that Evan does can be copied by the BTC dev team if they think it's good enough and they will (self admited), unless he keeps all the stuff closed source, which consequently makes it a no-no and no one will trust it. Not that I think he will come up with anything revolutionary after promising ring signatures in V2 then back peddling. On the other hand, they will never be able to copy cryptonote technology.
Ring signatures are superior and solve all the centralized-like problems, the blockchain bloat thing is nothing but FUD. I dont care if you are using MRO (the best option right now) or any of the cryptonote forks, they are all better options than a BTC fork.