I also haven't heard about pandacoin. Darkcoin is pretty nice coin but, IMO, it's better tom invest in BCN, BBR or DOGE !
note it
I can't imagine that Doge will survive this year. Yes it has his up and downs but as a simple gen. 1 copy coin with no special attributes, it would be hard to see this coin in 2015 still alive.
There is just less support for panda coin, so they will also get big problems. Without supporting people, you definitely can't survive.
My fully support goes just to a few coins atm.
For me personally NEM could be that big player I was looking for a long time.
Especially since you can see or read everywhere threads about NEM. Some of supporters, some of hates. That itself shows me, people are talking about NEM and have discussions about it.
That is a first signal for the popularity of NEM.