(Grandfathered) Travelocity Rewards AMEX. The grandfathered version featured 4% rebates on all purchases for use on Travelocity on virtually everything they sell (except cruises). Rebates are 8% for Travelocity purchases.

The reward system for this card is currently broken and all redemptions have to be processed by customer service -- which they do slowly. If they ever get the automated redemption straightened out, this is the best card on earth.