Here are my favorites:
Birds and Butterflies of Paradise
Fantasia for Theremin, Oboe, String Quartet, and Piano
Oboe Concerto - 3rd Movement
Viola Concerto - Premiere movement
Trio for Flute, Cello, and Piano
Symphony No. 4
The Greek Passion
What I notice most about Martinů more-so than many other composers is his original style that is detectable in ALL of his public works. It's absolutely fascinating.