Ahh, Memrise!
I'm a Duolingo user myself but i did enjoyed using Memrise.

Pros:

• Very gamified learning activities that makes learning almost addictive
• Modular teaching so that users need only spend less than 3 minutes to learn something

Cons:

• Very difficult to use on Free Version.

Overall I realize there are many ways to learn a language for free and it all depends on how one uses the different resources to his/her advantage. There are no more excuses to not learn new language to improve ones prospect in life.