Augustine, Harmony of Luke -- Somewhat helpful. Recommended if interested in Augustine.
John Calvin, Harmony of Matthew, Mark, and Luke -- Calvin is too prone to assume a single theological referent for a historical event in all three of the gospels instead of allowing for multiple referents using the same event. Otherwise very helpful. Recommended.
John Gill, Mathew to John -- Very helpful development of Jewish background from primary sources. See above on Calvin. Recommended.
Walter L. Liefeld, The Expositor's Bible Commentary: Luke -- Some very helpful insights. Recommended.
I. Howard Marshall, The Gospel of Luke (NIGTC) -- Basically orthodox but too prone to assume higher criticism. Some good work in the Greek.