What coin caught your eye and why?
The first coin that caught my attention (after bitcoin) was Goldcoin (GLD) and it was for the obvious reason - it had the best name by far.
But then I started to learn more about the secret development that was ongoing and the developer's plan to release a state of the art java client with a 51% attack defense system. Then I started to look at the community to get a well rounded picture of the coin.
What I discovered was that the market had somehow severely undervalued the coin and I could obtain it for a mere one-cent per coin. It has a similar circulation to Litecoin which is $14.00. But why was litecoin $14 and goldcoin $.01? Sure there should be a difference, but not a complete and total disconnect.
So it was a no brainer for me to invest at one cent and now hold until the market discovers the true value of this golden coin.