This study is a comparative analysis of thermal conversion technology options through data evaluation and assessment of reference plants that process municipal solid waste (MSW). A combined extensive literature review and multicriteria analysis was applied to determine the optimal Waste-to-Energy (WtE). The main focus of the study is to identify and examine the specific thermal conversion technologies with proven reference plants for energy generation. The “availability of reference plants” was used as a key criterion for the study, resulting to the different types and categories of thermal conversion technologies, such as conventional incineration (grate incineration, fluidized bed combustion), pyrolysis (rotary kiln), gasification (fixed bed, fluidized bed, moving grate) and plasma gasification. While comparative aspects, such as technological, economic, quality of feed, and environmental, were formulated to further analyze and investigate the reference plants. Finally, the evaluation of technologies presented a summary of reference plants showing the comparative analysis of WtE options in terms of capacity, power production, cost, calorific value, emission and residues, etc. Overall, gasification and pyrolysis are the better option in terms of emission, capital cost, quality of feed, and power production while still being competitive in terms of capacity.