I figured I'd save Crazy some time and effort. All attendance increases are for the game day only.
Retro Game Day - Costs $75K | increases attendance by 15% on average | can be scheduled once per year
Baseball Cap Day - Costs $100K | increases attendance by 20% on average | can be scheduled once per month
Noddin Head Doll Day - Costs $250K | increases attendance by 45% on average | can be scheduled once per month
Bat Day - Costs $125K | increases attendance by 25% on average | can be scheduled once per month
Glove Day - Costs $150K | increases attendance by 30% | can be scheduled once per month