I reckon there are lots of reasons for this:
-the books you read in Eng Lit/other literature classes are pre-selected as "good books" to some extent anyway
-you are "taught" to read them, helped to understand them, they are probably the books you ever read in the greatest detail, therefore, unless you actually dislike reading (or the books themselves), the process will bring you immense pleasure. Let's face it, few of us in later life have the time or energy to read with the depth and attention you give a book at, say, A-Level. So those are the ones that stick in your mind.
-a lot of us at this parenting stage in our lives read purely for pleasure and are usually practically comatose by the time we have any time to ourselves to read, so our mental energy is sorely diminished for more ambitious books. So recent favourites might be less ambitious than "all-time" favourites discovered at school.
-we read less? (All of the above probably true for me anyway)
I put this on the other thread I read back-to-back with this yesterday (about books we were unable to finish) but I will repeat it - the vast majority of titles feature frequently on both threads. Ergo: those whose favourites matched some of the unreadables on the other threads might find even more reading material there IYSWIM...
Anyway, give us your list now you've commented so acerbically on everyone else's