Very few characters on a television show have the same depth as CSI's former front man, Gil Grissom (William Petersen). Appearing in almost every single episode since the pilot of the show until season 9, this loveable Ph.D. was the show's protagonist, and did an excellent job of leading a team of crime scene investigators in the Las Vegas area. Grissom has a close relationship with his team as many of them he handpicked himself, such as Nick Stokes (George Eads), a former hair and fiber analyst from Dallas and Sara Sidle (Jorja Fox), whom he met while she was auditing his lecture in San Fransisco.

In addition to being a crime scene investigator, Grissom is also an entomologist. He is very knowledgeable about insects and applies this knowledge to solving cases. His nickname is "The Bug Man" as his office was a backdrop for a variety of specimens, such as a fetal pig and a two-headed scorpion. In the pilot episode, one of Grissom's team members tells him "No offense but I don't think I wanna eat anything that's been in this office. Is there a grasshopper in here?" Even after he retired and Nick Stokes took over as supervisor, the fetal pig remained in the office as Grissom's colleagues felt it belonged there.

Grissom was a crime scene investigator for roughly 22 years when he began to show signs of a burnout in season 7. He left the lab for four weeks to teach a class at Williams College in Massachusetts. When he returned, he appeared refreshed and told Warrick Brown (Gary Dourdan) that he "missed" Las Vegas. This burnout would resurface after his fiance resigned from the lab and Warrick was murdered.

Grissom is dedicated to his work because "the dead can't speak for themselves". This is the reason he became a crime scene investigator. His outlook speaks volumes for the personality of his character as he is seen dealing with personal demons while solving crimes and seeking justice for the victims.

Grissom and Sara developed a romantic relationship although they had many obstacles thrown in their path from his hearing loss to Sara's difficulty with alcoholism. At the end of season 7, Sara was kidnapped by The Miniature Killer (Jessica Collins). It was a race against time to find her as the team searched for clues and interrogated the killer who had severe mental problems. Sara's brush with death caused her to become depressed and even though she and Grissom were engaged to be married, she left the crime lab. Grissom found it difficult to focus after she left and seemed to have lost the enthusiasm and wit he was known for. In the latest season of CSI, it is revealed that they are married and living in Paris.

Best Quotes:

"I need you to roll up your sleeve and give me a pint of your blood."

"We look at each case objectively, without presupposition, regardless of sex, creed, color, or bubblegum flavor."

"He manipulates people. The public assumes that scientists are ethical, but many of us are no better than politicians, evidently."