Come on now which ones do you think are overrated? That's what this thread is for. :-)
Dos Passos, while I like his work a bit, shouldn't be on this list. I think the gothics are under-represented, too. Matthew Lewis' The Monk deserves a look, and so does James Hogg's Private Memoirs and Confessions of a Justifiable Sinner.
I'm still trying to catch up, but i will pass on my druthers...