Originally Posted by KRSW

Price Protection:

Citi -- Up to 60 days after purchase, up to $500 per incident, up to $2,500 per year.
EXCLUDES: Going Out-of-Business Sales, Auctions, vehicles & their parts, food/medications, tickets (airline/concert), jewelry, collectables, items for resale, services (that are not goods), anything with a service contract (cell phone), items with rebates, refurbished or used items.

Chase -- Up to 90 days after purchase, up to $500 per incident, up to $2,500 per year per card.
INCLUDES: ads for Cash Only sales, close-out/liquidation/going-out-of-business sales but only $50 per incident on these.
EXCLUDES: flea markets, limited quantities, seasonal sales, auctions, discounts of seasonal items, same as Citi from here.
NOTES: MUST file claim within 21 days of the advertised price.

Amex -- NONE. Again, Amex Plat is the highest priced card out of the bunch but fails to deliver.

Winner: Chase. 90 days vs. 60 for Citi AND Chase pays quickly. I know others may disagree with me, BUT I'm going by my experiences.