Funny is subjective. Popular is a better measure:

CBS had another great night on Monday, with Two and A Half Men scoring a win among total viewers and adults 18-49. It was the last original episode the network had in the can before the comedy went on a forced hiatus, so interest in Charlie Sheen and Co. remained strong: It was the most-watched show of the night with 14.5 million viewers, and averaged a timeslot-winning 4.2 rating/11 share in adults 18-49, according to preliminary estimates

The re-runs are presently scheduled to be in syndication for the next 10 years with Warner Brothers getting $1B (yes, billion) in potential syndication fees; CBS pays $4M per episode, which includes Sheen's approximate $1.9M/episode salary, which means that ad revenue back to CBS must be huge.