I don't have a great deal of actual experience, but I love the deals at the QC Bandits game.
$2 Tuesdays. Any home game on a Tuesday. General Admission $2. Plump hot dog $2. Soft drinks $2. The biggest expense is parking: $5.
They also have some Beer night (I think Keystone?) for $2 certain nights
I'm a cheap date, baby!