Each year up to 1% of the papers published during the previous year are selected for the IEEE Systems Journal's Best Paper Award. The selection process is based on evaluations made by the reviewers and the Associate Editor. All Editorial Board members are involved in the process, although the Editor-in-Chief’s role is to monitor the process. Last April, five papers published during 2020 were selected for the IEEE Systems Journal's Best Paper Award, and the authors of the papers were subsequently notified accordingly. Given the large number of high-quality papers published in this journal, the Selection Committee had a difficult choice to make again this year; I take this opportunity to thank each committee member for your hard work. As with previous issues of the IEEE Systems Journal, this issue also contains numerous applications of complex systems and system of systems. The topics include hybrid brain/neural control, brain-machine interface, wireless sensor networks for healthcare applications, human action recognition, reducing the spread of spam in social networks, smart manufacturing systems, energy harvesting networks, secure industrial IoT, renewable energy sources in power grids, DC nanogrids, cybersecurity in smart grids, next-generation satellite systems, vehicle-to-vehicle communication, connected vehicles in long tunnels, indoor wireless communication, infrastructure-free indoor navigation (as represented by the cover picture), and many more. Several of these papers tackle emerging technologies, and we sincerely hope that they will help the systems community in advancing these rapidly growing research areas for the benefit of humanity