<p>Over the past few years, conductive polymer composites (CPCs) have gained considerable interest due to their multifaceted applications. This review comprehensively analyzes existing research on the electrical conductivity behavior of HDPE composites reinforced with single conductive fillers as a function of filler volume fraction. The effect of filler’s type, size and their distribution on matrix is deeply studied. By aggregating and comparing data from numerous studies—spanning carbon-based fillers, metal base fillers and organic fillers, we were able to benchmark their performance under similar loading scales. Through this comparative analysis, we identified the most effective HDPE-filler system reported to date in terms of conductivity enhancement. To the best of our knowledge, no previous review has systematically combined such a diverse set of results to unambiguously identify a “best-in-class” solo filler for enhancing composite’s conductivity. A maximum conductivity of 6.8⋅10⁴ Sm^− 1 is observed with Silver Polyamide (AgPA) coated matrix at a very low filler content of 4–5 volume %, whereas least electrical conductivity of 1.31⋅10^− 11 Sm^− 1 is observed for Aluminium (Al) fillers, with a wide range of 5–30 volume % to reach percolation. Given the increasing demand for lightweight and cost-effective conductive materials, the findings can help drive future material design methods. This provides a valuable reference point for researchers aiming to optimize conductive HDPE composites and sets a clear target for future experimental development. Our analysis serves as a useful resource for both academic and industrial researchers working in this field.</p>