In "Lie to Me" which premieres tonight at 9, Tim Roth plays Dr. Cal Lightman, a scientist who's an expert on facial expressions and body language. He has his own firm, so he works as a consultant on various cases for whomever can afford to hire him. Kelli Williams ("The Practice") plays his right-hand woman.
Roth's character is a scientist, Baker's is a former con man who learned his techniques through observation. So, "Lie to Me" feels more procedural; it explains all the techniques along the way (although not as clumsily as the "CSIs"). Roth's character would probably hire Baker and try to train him.
Roth's character is divorced with a teen daughter. Baker's family was murdered, part of the backstory that changed his life.
Baker is all charm in "The Mentalist"; Roth's character is quirky, an oddball genius with a sensitive soul.
"The Mentalist" makes you feel that Baker, because he's so charming, has this special gift.
"Lie to Me" makes you feel like the information he has is accessible and that's a little uncomfortable because Roth can always tell when someone is lying (the show even uses real-life examples) and do you really want to know that someone is lying to you every time it happens? Think about it.
Finally, Simon Baker is a hottie. Tim Roth's looks are interesting.