As the number of online and blended learning courses offered by higher education institutions increase, a predominant issue for instructors is their design. This study focuses on the selection of appropriate media to support online and blended learning (OBL) activities. To this end, we mapped and synthesized in two consecutive systematic review studies the effectiveness of particular media formats on students' learning outcomes. Eleven empirical studies with a quasi-experimental research design and thirteen studies with randomized allocation to treatment conditions were selected for a detailed analysis. The cumulative findings indicate that ten particular media attributes are of paramount importance for effective learning in OBL courses: interactivity, navigability, (a)synchronicity, flexibility, media richness, ease of use, individualization, mobility, proximity and responsiveness. Furthermore, while the study affirms the theoretical underpinnings regarding multimedia learning and media richness, it exposed that further scrutiny in the field of media selection for application in natural settings of OBL is necessary. Future directions for research are proposed. The outcomes may be useful to OBL instructors and instructional designers in higher education.