Here's some older ones I'll offer, because there were, of course, quotable quotes in movies a long time before many on this board ever got a chance to watch flicks.
Watching new movies on DVD is very cool, but I think the opportunity to watch old, real old and even very, very old movies is the schiznit.
Here's some I remember:
Henry Fonda's rambling story to Jimmy Stewart, over the opening credits of "The Cheyenne Social Club."
Henry Fonda at the end of "The Grapes of Wrath."
Jack Nicholson in "Five Easy Pieces," while ordering food from a particularly *****y waitress.
"Sgt. York," played by Gary Cooper, was a man of very few words, so there weren't many long speeches by him in that movie. However, what his commanding officer or his mentor back home, played by Walter Brennan, said to him about defending things dear to him was memorable.
Rosie O'Donald in "Beautiful Girls."
Steve Martin in "Roxanne."
Marlon Brando in "Julius Caesar," Shakespeare's words, his delivery. Marlon has many good ones in other films, like "On The Waterfront" and "Apocalypse Now."
Woody Allen in "Annie Hall" and all of his movies.
Mozart didn't say much with words either, but F. Murray Abraham as Salieri describes the genius and his own frustration a couple of times in "Amadeus."
Vivien Leigh as Scarlett O'Hara has a couple in "Gone With The Wind."
Christopher Walken, delivering a watch to a comrade's son, in "Pulp Fiction."
Robert Shaw, as Quint, about the USS Indianapolis being torpedoed, in "Jaws."
Those are some good ones.

Wow, look what I found in cyberspace!!!!
Check these sites out and watch a good, quotable movie, new or old whether you're young or old:
http://www.whysanity.net/monos/http://www.filmsite.org/bestspeeches10.html
Gig 'em, FAST FRED '65.
Before the world wide web, village idiots usually stayed in their own village.