I'm very bullish on Quark, for a number of reasons. If you ignore coinmarketcap.com, which hasn't updated a number of coins today, Quark currently has a market capitalization of around ~80 million, bringing it into fourth place.

It looks like a junk coin because of the number of units in circulation, but I consider this to be an advantage because it's much more fungible than BTC or LTC. There's a lot of hot air being made about the 'hold vs. spend' paradox of BTC as money, and I believe the distribution of Quark solves this for quotidien transactions. Further, it has a .5% inflation rate, meaning a set 1 million Quarks mined per year; this to me encourages circulation.

I'll copy what I posted in another thread:

The top ten cryptos by market cap. are BTC (SHA256) LTC (Scrypt) Peercoin (SHA256) Quark (6-Factor) Namecoin (SHA256) Megacoin (Scrypt) Feathercoin (Scrypt) Primecoin (SHA256) Protoshares (POW) Worldcoin (Scrypt).

I firmly believe that the most secure top-runners should have difference hashing algorithms to prevent market panic if crypto flaws are found. Imagine if we received a Snowden/Greenwald expose that indicated that SHA had been compromised by either a private or national entity; consider the market panic that would ensue in that case. BTC/LTC/Quark (I know, I know, as Max Keiser says) makes sense to me. They each use different hashing algorithms and could, in theory, absorb market fluctuations from each other in the case of attack.

Protoshares has a very interesting ASIC resistant algorithm, but they aren't at all meant to be used in a currency context; much like namecoin, they have a specific niche that they fill.