Tom Hanks's first hit movie was this adorable romantic comedy that's every bit as much fun today as it was back in the early 80's. Daryl Hannah is a mermaid who washes up onshore to track down Hanks's Allen Bauer, whom she believes is her true soulmate, and a literal fish out of water story progresses as she learns English, goes shopping, watches TV, goes ice skating and gets used to life in New York City. Eugene Levy is the government scientist charged with capturing her, but the appeal of this film comes strictly from the chemistry between Hanks and Hannah, and the scene stealing antics of John Candy and Levy in comedic support. Everyone is great in this movie, they all play their parts to the tee and that's why it still holds up today. If they were to make this movie now they'd probably think they needed an explanation or more examination of how mermaids can actually exist, but a fantasy premise like this really doesn't need it- she's a mermaid, she's here and you have to accept it. So simple that it works like a charm.
Original 1984 Trailer: