The record for msot centuries in a first-class career is held by Egnland batsman Jack Hobbs, who scored 199 first-class centuries in 1325 innings.
A batsman is considered to have scored a century when he completes a score of 100 runs off his bat. Extras, byes etc are not counted in a batsman's score. Sachin Tendulkar and Brian Lara are two bastmen who have the most number of centuries in cricket.
sachin
martin Crowe
Mathew hayden
sachin tendulkar
sachin tendulkar
Michael clarke
ricky ponting
Sachin and Sehwag. with 6 each
Ricky ponting
As of May 2012, the batsman who has scored the most runs in Twenty20 cricket is David Hussey, who has scored 4480 runs in 173 innings (from 180 matches), including a top score of 100 not out. His current Twenty20 average lies at 31.77.