Electrochemistry: Oxidizing agents

Which one of the species above is the best oxidizing agent?

Zn2+(aq)+2eZn(s)Eo=0.74VCu2+(aq)+2eCu(s)Eo=+0.34VCo2+(aq)+2eCo(s)Eo=0.28VAg+(aq)+eAg(s)Eo=+0.80V\def\arraystretch{1.5}\begin{array}{cc}Zn^{2+}(aq)+2e^-⇌Zn(s)&&E^o=-0.74V\\ Cu^{2+}(aq)+2e^-⇌Cu(s)&&E^o=+0.34V\\ Co^{2+}(aq)+2e^-⇌Co(s)&&E^o=-0.28V\\ Ag^+(aq)+e^-⇌Ag(s)&&E^o=+0.80V\end{array}

More Reduction Potentials Questions: