Youtube has it online, divided into 10-minute segments. Here's the first 10 minutes:
The other parts are linked at Youtube: part 2, part 3, part 4, part 5, part 6, part 7, part 8, part 9
It's listed as one of the 1001 Movies You Must See Before You Die. Slant Magazine gives it 4 out of 4 stars and says, "the film's most astonishing feat is the vulnerable and charming performances the director finesses from two of musical comedy's most impenetrable vocalists: Maurice Chevalier and Jeannette MacDonald." DVD Talk calls it "the best musical of the early-talkie era" and says, "even film fans who normally don't like musicals will enjoy Love Me Tonight for its enormous wit". Rotten Tomatoes has a critics score of 100%.