According to CelebrityNetWorth.com, the most valuable baseball card is the T206 Honus Wagner, which was released between 1909 and 1911. It is estimated that fewer than 100 of these cards exist, the most expensive of which sold for $2.8 million in 2007.
The second most valuable baseball card is the 1914 Baltimore News Babe Ruth, which has sold in excess of half a million dollars. In the third spot is the T206 Joe Doyle card, worth around $300,000. This value applies only to a misprinted version of the card that lists Joe Doyle on the wrong team. The corrected card is fairly common and not worth a premium. The fourth most valuable card is the 1952 Topps Mickey Mantle. Due to Mantle being a superstar player, this card can fetch up to $280,000 in good condition.
The number five spot goes to the 1933 Goudey baseball card featuring New York Yankee Lou Gehrig on the front. This card can sell for up to $275,000. Rounding out numbers six through 10 are the 1911-1914 General Baking Company Ty Cobb, the 1910 Standard Caramel Honus Wagner, the 1914 Boston Garter "Shoeless" Joe Jackson, the 1910 T210 "Shoeless" Joe Jackson and the T206 Eddie Plank.