Best third party keyboard for Android?

Hey guys,

I was just wondering. I have been using the vanilla keyboard on my Samsung Galaxy S4 for some time now, and I was wondering what could be a good replacement for the stock one.

I heard about swift key. That it was like the best third party keyboard out there but I wanted to know if there are more keyboards to look into. I want like the best of paid and of free to compare.

Do any of you have any tips to help me out? Thanks!