I wish I could reply more "on target," but I really don't have the time to research which was Chopin's first waltz.However, I really like Chopin's waltzes. For some inexplicable reason, I seem to have a knack for them. There were 17 of them, all told, I think.It is less important which is hardest -- and thus reflects more credit if one can play it -- than identifying the waltzes that one LIKES the most. Hard or easy, if you really like it, learn it and play it. [Of course, this assumes leaving out the ones that are technically beyond a person -- which is my situation with a number of them.]With Chopin's waltzes especially, it is one thing to play them, and another thing entirely to really play them well.I find that I learn pieces I love very rapidly. I just practice and practice, and the time slips by.One I really enjoy a lot is Op. 34, No. 2.Regards--