I have such fond memories of watching Abbott and Costello movies with my Dad when I was young.  As goofy and corny as they were, they were also just plain fun to watch. And they still are. I now have the collection of all their movies on DVD and pull them out every now and again just to enjoy their simplicity.  These are my favorite 10 (listed by year released):

1. Buck Privates (1941) Directed by Arthur Lubin
2. Hold That Ghost (1941) Directed by Arthur Lubin
3. Hit the Ice (1943) Directed by Erle C. Kenton & Charles Lamont
4. In Society (1944) Directed by Jean Yarbrough
5. Here Come the Co-eds (1945) Directed by Jean Yarbrough
6. The Naughty Nineties (1945) Directed by Jean Yarbrough
7. ***The Time of Their Lives (1946) Directed by Charles Barton
8. Jack and the Beanstalk (1952) Directed by Jean Yarbrough
9. Abbott and Costello Meet Dr. Jekyll and Mr. Hyde (1953)Directed by Charles Lamont
10. Abbott and Costello Meet the Mummy (1955) Directed by Charles Lamont

(*** My very favorite)

If you have not indulged in some classic Abbott and Costello, you can check out YouTube for some clips of their best routines.