Cobb led the American League in hits 8 times, 2Bs 3 x, 3Bs 4x, HRs once, RBIs 4 x and SBs 6 x. He also won 11 batting titles, led the league in OBP 8 x, SLG 8 x and OPS 10 times in his career. After being up in 1905 for part of his first season, he hit over .300 every year of his career including 3 years where he hit over .400. He scored 2246 runs for his career, had 4189 hits, 724 2B, 295 3B and 1935 RBI, including 7 years of 100 + RBI. He also finished with 897 stolen bases.
When he was inducted in Baseball's Hall of Fame in 1936, he received 98.2 % of the vote by the Baseball Writer's Association, more than Babe Ruth and Honus Wagner, who were also among those inducted in the first year. He finished with a .366 career average, a record that will never be topped to go along with an impressive .433 OBP and .512 career SLG percentage.
I find it hard, from a numbers perspective, to prove there was a better all around player in the history of this game. Ruth has the homeruns, Tris Speaker was comparible, but not better. Even though Pete Rose and Rickey Henderson surpassed his records for hits and stolen bases, respectively, they can not be mentioned in the same breath as the great Ty Cobb.