That's a very difficult question, since Lana Turner starred in so many good movies and is very underepresented on dvd. My choices would be:
Two Girls on Broadway Honky Tonk Johnny Eager Keep your Powder Dry Green Dolphin Street Cass Timberlane
Though I think some of those could be included on boxes dedicated to her co-stars (Gable, Taylor and Tracy)
In fact I would be glad if any of these other choices would be included: These Gamour Girls Dancing Co-ed (lI love Lana in her early vehicles) Somewhere I'll find you Slightly Dangerous Marriage is a Private Affair Weekend at the Waldorf Homecoming
Vol. 1 Diane Green Dolphin Street A Life of Her Own Marriage Is a Private Affair Somewhere I'll Find You Two Girls on Broadway
Vol.2 Keep Your Powder Dry Slightly Dangerous Latin Lovers Flame and the Flesh We Who Are Young Bachelor in Paradise Dancing Co-Ed &These Glamour Girls(double feature)
"Mr Imperium" & "The Merry Widow" in Musical sets "Week-End at the Waldorf" in Ginger Rogers set "Cass Timberlane" in Spencer tracy set "Johnny Eager" in Robert Taylor set "Betrayed" & "Homecoming" & "Honky Tonk" in Clark Gable set