I'm currently learning Spanish, and have to say that I don't find noun gender to be a huge problem, as generally (apart from some exceptions) if it ends in 'a' then it's feminine, and if 'o' then masculine. Compare that to German, which has no general and easy mnemonic for guessing a noun's gender, adds an additional gender, has a grammatical system where the article attached to a noun changes to that of another gender depending on case, and then to top it all off has no standard rule for creating a plural from the noun singular...