So my friends and I started a league and you can't play anything but commons in your deck. This got me wondering what were some of the best common cards out there. I play standard and modern but I mostly play Jund and Bug so I came up with these as a start:
{doom blade}
{mana leak}
{preordain}
{ponder}
{delver if secrets}
{searing spear}
{tragic slip}
{pacifism}
Also forgot to add
{arbor elf}
{farseek}