I think I'm thinking about the romance story in the film, not the greatness of the film itself. If the romance is pretty flawed (Darling, Double Indemnity, Streetcar Named Desire, Unbearable Lightness of Being) then I may have moved it out of the top 100, or left it off altogether (Sunset Boulevard, Who's Afraid of Virginia Woolf?). Though in some cases, these romances can be psychotic (50 First Dates, Crazed Fruit, Dangerous Liaisons, Eternal Sunshine, Morgan!, Ugetsu), and still be powerful.
AA = best picture Oscar®
In alphabetical order
50 First Dates (2004)
A Good Year (2007)
A Life Less Ordinary (1997)
A Room With a View (1985)
A Very Long Engagement (2004) France
Adam's Rib (1949) bw
Alice (1990)
Amadeus (1984) (AA)
An Education (2009)
An Ideal Husband (1995)
Annie Hall (1977) (AA) [photo rt]
As Good As It Gets (1997)
Atonement (2007)
Beautiful Girls (1996)
Beauty and the Beast (1991)
Big (1988)
Body Heat (1981)
Brideshead Revisited (1981) tv
Brothers (2004) Denmark
Carmen (1983) Spain
Casablanca (1942) bw (AA)
Chocolat (2000) France
Closer (2004)
Crazed Fruit (1956) Japan, bw
Crouching Tiger, Hidden Dragon (2000) China
The Cuckoo (2002) Russia
Dangerous Liaisons (1988)
Defending Your Life (1991)
Doctor Zhivago (1965)
Dreamland (2006)
The Earrings of Madame De.. (1953) France, bw
Eternal Sunshine of the Spotless Mind (2004)
The Fabulous Baker Boys (1989)
Finding Neverland (2004)
Fire (1995) India
The Fountain (2006)
Gadjo Dilo (1998) Romania
The Gay Divorcee (1934) bw
The Girl in the Cafe (2005)
Gone With the Wind (1939) (AA)
Good Will Hunting (1997)
The Graduate (1968) [photo rt]
The Grey Fox (1983)
Groundhog Day (1993)
Hannah and Her Sisters (1986)
Heat and Dust (1983)
Heaven Can Wait (1978)
His Girl Friday (1940) bw
Il Postino (1995), Italy
The Importance of Being Earnest (2002)
In a Lonely Place (1950) bw
In the Mood for Love (2001) Hong Kong [photo rt]
It's a Wonderful Life (1946) bw
Kinamind (2005) Denmark
The Lady Eve (1941) bw
The Last Station (2009)
Lost in Translation (2003)
Love and Pain and the Whole Damned Thing (1972) - bittersweet story with Maggie Smith and Timothy Bottoms is sadly not available on dvd but TCM recently aired it so maybe one day; an older woman with a terminal illness living her last days traveling in Europe meets a young student drifting around Spain
Manhattan (1979) bw [photo rt]
McCabe and Mrs. Miller (1971)
The More the Merrier (1943) bw
Morgan! (1966) bw
Much Ado About Nothing (1993)
My Brilliant Career (1979) Australia
My Fair Lady (1964) (AA)
My Favorite Wife (1938) bw
The Namesake (2006)
Now, Voyager (1942) bw
On Golden Pond (1981)
Out of Africa (1985) (AA)
Parenthood (1989)
Peggy Sue Got Married (1986)
The Philadelphia Story (1940) bw
Pride and Prejudice (2005)
Raising Arizona (1987)
The Road Home (1999) China
Say Anything (1989)
Shakespeare in Love (1998) (AA)
Shall We Dance? (1995) Japan
The Shop Around the Corner (1940) bw
Sideways (2004)
Sunrise (1927), bw-silent
The Thin Man (1934) bw
The Time Traveler’s Wife (2009)
To Have and Have Not (1944) bw
To Live (1994) China
Ugetsu (1953) Japan, bw [photo rt]
Under the Sun (1998), Sweden
Vatel (2000) France
Wall-E (2008)
Water (2005) India-Canada
We of the Never Never (1982) Australia
West Side Story (1961)
When Harry Met Sally (1989)
The Wings of the Dove (1997) Helena Bonham Carter's best performance, and Oscar® nominated, winner of 13 other awards
Witness (1985)
Women in Love (1970)
Zelary (2003) Czech Republic [photo right]
Zhou Yu's Train (2004) China
Here's 55 more 'honorable mentions'
A Beautiful Mind (2001)
A Streetcar Named Desire (1951) bw
Alice Doesn’t Live Here Anymore (1975)
After the Wedding (2006) Denmark
American Beauty (Sam Mendes, 1999) (AA)
An American in Paris (1951) (AA)
Atlantic City (1980)
Australia (2008)
Baby Boom (1987)
Back to the Future (1985) "You are my density"
Baran (2001) Iran
Blast From the Past (1999)
Born Yesterday (1950) bw
Brazil (1985)
Breaking Away (1979)
Broadcast News (1986)
The Buccaneers (1996)
Bull Durham (1988)
Clueless (1995)
The Curious Case of Benjamin Button (2008)
Darling (1965) bw
Diva (1981) France
Double Indemnity (1944) bw
Down With Love (2003)
Election (1999)
Elevator to the Gallows (1958) bw
Emma (1996)
Five Easy Pieces (1970)
Heaven Can Wait (1978)
Heavenly Creatures (1994) New Zealand
House of Games (1987)
It's Complicated (2009)
Jean de Florette/Manon of the Spring (1986) France
Jezebel (1938) bw
Jodhaa Akbar (2007) India
The King and I (1956)
The Last Picture Show (1971) bw
Like Water for Chocolate (Alfonso Arau, 1992, Spain)
Malena (2000) Italy
Mr. and Mrs. Iyer (2002) India
Mrs. Miniver (1942) bw (AA)
My Blueberry Nights (2007)
Nelly and Mr. Arnaud (1995), France
On Her Majesty's Secret Service (1969)
Out of the Past (1947) bw
The Player (1992)
Reds (1981) [photo rt]
Return of Martin Guerre (1982) France
Revolutionary Road (2008)
The Secret in Their Eyes (2009) Argentina
Sex, Lies, and Videotape (1989)
Singles (1992)
Slumdog Millionaire (2008) (AA)
Terms of Endearment (1983) (AA)
The Unbearable Lightness of Being (1988)
Veer-Zaara (2004) India
Vicky Christina Barcelona (2008)
Walkabout (1971)
All I can say about Harold and Maude is "euwwwwww!!!! As if!!"
My favorite 10? (for the romance, not the film overall)
1. Hannah and Her Sisters
2. My Fair Lady - though I prefer the original cast recording with Julie Andrews in the role of Eliza Doolittle
3. When Harry Met Sally
4. Shakespeare in Love
5. A Room With a View
6. Beautiful Girls
7. An Education
8. Dangerous Liaisons
9. In a Lonely Place
10. Groundhog Day; Zelary; The Namesake