Amazon offers its Prime members the GE Nighthawk Platinum Headlight Bulb 2-Pack in four styles for $18.99. This $10 mail-in rebate cuts it to $8.99. With free shipping, that's $11 under our summer mention and the best deal we've seen for these bulbs. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.58.) They purport to give up to 90% more light than standard halogen bulbs. Rebate ends December 31.