Ways to make the game more interesting (apart from challenges)

Thanks for all the suggestions, they're very much appreciated :) Now that some of you mentioned it, I like the idea of changing the rules of challenges a bit, since many of them seem really unfun to me with their original rules (i.e. living on the same lot all throughout the legacy challenge). Maybe I'll also just spend some time just building and looking for stuff I've never done before. Nice ideas everyone, I'll keep them in mind next time I start the game! :)