Lew Ayres
This earnest, boyishly handsome star of the pacifist classic "All Quiet on the Western Front" (1930) was extremely prolific during the 1930s, at first primarily at Universal Studios, and then also at Fox and Paramount. Although a very talented and sensitive actor, Ayres found his early stardom fade during the decade as he was cast in either trivial light comedies which suited his gentle manner or in films which called for tough, streetwise characterizations which didn't always suit him. He gave an excellent performance, though, as Katharine Hepburn's drunken brother in George Cukor's "Holiday" (1938) and enjoyed considerable popularity in a series of Dr. Kildare films at MGM in the late 30s and early 40s. His career faded during WWII after he declared himself a conscientious objector, but he received renewed respect when he served bravely in a non-combat medical capacity.