Recall to avoid offending too many people, I restricted my list to bloggers, pundits and politicians. I count people who call themselves libertarians. I don't to list personal friends (friends -- I like to keep them).
Eugene Volokh (not reasonable re appropriate punishment of an Iranian murderer)
David Brooks (not always honest)
Arnold Kling (not really reasonable but very honest)
Olympia Snowe (not really conservative or honest but I'm getting desperate)
Scott McClellan (not really et. but gets extra points for near honesty in a press secretary)
Richard Clarke (oh you don't think he's conservative -- read "Against all Enemies")