Great Expectations, Beowulf, Frankenstien, Grapes of Wrath, The Pearl, A Raisin in the Sun, All the King's Men, All Quiet on the Western Front, David Copperfield (never finished that one), and so many more I'm sure.
Really, there are few, if any, "classics" that I've read that I would say I really enjoyed. Some more...modern classics, I suppose, are pretty good. Depends on your definition of that I guess. But most of the things people that believe you must have read to be "well-read" are just awful.