I have always thought of Milton Friedman as a reasonable economist. I suspect if presented with alternative libertarian viewpoints, he would consider them, if not adopt them. For any forum members unfamiliar with him, below are some videos of him I liked:
Milton Friedman - Free to Choose 1990 - 1of 5 The Power of the Market PL 1/5
http://www.youtube.com/watch?v=Yndxvj6813c
Milton Friedman - Free to Choose 1990 - 1of 5 The Power of the Market PL 2/5
http://www.youtube.com/watch?v=dBOHpKNzxHw
Milton Friedman - Free to Choose 1990 - 1 of 5 The Power of the Market PL 3/5
http://www.youtube.com/watch?v=12cTb4_9aLQ
Milton Friedman - Free to Choose 1990 - 1 of 5 The Power of the Market PL 4/5
http://www.youtube.com/watch?v=-YXcfd51kCA
Milton Friedman - Free to Choose 1990 - 1 of 5 The Power of the Market PL 5/5
http://www.youtube.com/watch?v=2JTEjsXGSwI
Milton Friedman on Donahue 1980 (1/5)
http://www.youtube.com/watch?v=OE1nJJBoxvk
Milton Friedman on Donahue 1980 (2/5)
http://www.youtube.com/watch?v=LTK2ul76oYc
Milton Friedman on Donahue 1980 (3/5)
http://www.youtube.com/watch?v=8E3jDdNTFXE
Milton Friedman on Donahue 1980 (4/5)
http://www.youtube.com/watch?v=MuS9QJ2IYSI
Milton Friedman on Donahue 1980 (5/5)
http://www.youtube.com/watch?v=eLJbtVZWOiY
Milton Friedman on Donahue 1979 (1/5)
http://www.youtube.com/watch?v=E1lWk4TCe4U
Milton Friedman on Donahue 1979 (2/5)
http://www.youtube.com/watch?v=5Lp2kGJASGY
Milton Friedman on Donahue 1979 (3/5)
http://www.youtube.com/watch?v=GapXLpLoZBs
Milton Friedman on Donahue 1979 (4/5)
http://www.youtube.com/watch?v=I0Ocv8aMBjk
Milton Friedman on Donahue 1979 (5/5)
http://www.youtube.com/watch?v=brBvdjoNC6Y