Nanoparticle research is a fascinating branch of science. The strongly size-related properties of nanoparticles offer uncountable opportunities for surprising discoveries. The often unexpected and unprecedented behavior of nanoparticles bears great potential for innovative technological applications, but also poses great challenges to the scientists. They have to develop highly controllable synthesis approaches, more sensitive characterization tools and finally new models and theories to explain the experimental observations. In this review, we discuss a personal selection of papers dedicated to nanoparticle research, which we believe provide an illustrative overview of current research directions in this rapidly developing field. We have structured the text in five sections: introduction, nanoparticle synthesis, formation mechanisms, nanoparticle assembly, and applications. The chosen examples within these sections are not directly related to each other, but reflect the remarkable broadness of nanoparticle research covering historical aspects, basic and applied science as well as commercial applications.