Oh finally, I have been able to add one more to the list:
1. The Last Island (1990, a feminist version of the castaway theme)
2. Cast Away (Tom Hanks, I really loved that film!)
3. Blue Lagoon (Brooke Shields & Christopher Atkins in sugary back to nature idylle.)
4. We're Not Dressing (Bing Crosby, Carole Lombard)
5. The Admirable Crichton
6. Lord of the Flies (I liked the 1963 version better than the 1990 remake)
7. Robinson Crusoe (there have been several movie versions, take your pick)
8. The Little Hut (S. Granger, Ava Gardner and David Niven)
9. Swiss Family Robinson
10. Six Days, Seven Nights (Harrison Ford & Anne Heche battle it out in a humourous way)
11. Miss Castaway and the Island Girls (2004, weird comedy with a cameo by Michael Jackson)
12. Hell in the Pacific (1968, Japanese and US soldier find themselves alone on a desert island during WWII)
13. Mysterious Island (Michael Callan, Joan Greenwood)
14. Heaven Knows Mr Allison - Robert Mitchum, Deborah Kerr. US soldier and nun stranded on Pacific Island during WWII hiding from Japanese.
15. Sea Wife = Richard Burton, Joan Collins. Four survivors of sunken ship land on island. Heroine (surprise, surprise) turns out to be a nun. (Yes! Joan Collins.)
16. Three (dribble with Billy Zane, a lush tart and an Hispanic servant)
17. Matango (1963, Japanese thriller about a desert island inhabited by killer mushrooms)
18. The Lost World: Jurassic Park II (1997) and Jurassic Park III (2001), which both are set on the abandoned island of Isla Sorna.
19. The Last Flight of Noah's Ark (1980, a fantastic tale involving a WWII bomber, its pilot, a nun, two orphans and two lost Japanese soldiers on a desert island)
20. Father Goose - During WWII boozing beachcomber Cary Grant is persuaded to observe enemy airplanes on a South Seas Island where he is later joined by Leslie Caron and her female students who had been stranded on a nearby island.
21: Mr. Robinson Crusoe (1932, an amusing South Seas comedy, but the attitudes towards women and natives is rather dated.)
22. Deux ans de vacances (This is the title of the Jules Verne novel, not the actual film I saw, because I do not know whether it was Dos años de vacaciones (1962) or Strange Holiday (1969). I saw it as a child with subtitles.)
23. Treasure Island (Many versions of which I have seen at least three, take your pick)
24. Mutiny on the Bounty (multiple versions) mutineers and Tahitian girlfriends find island and settle on it. There are still Pitcairn Islanders living there today.
25. Il Signor Robinson, mostruosa storia d'amore e d'avventure (1976, a spoilt city dweller washes up on the island of Robinson Crusoë)
26. Swept Away (2002, flop with Madonna stranded on a Mediterranean island)
Four to go and I already have one in mind (for the next trip to the DVD store).