I'll second those. The Pickwick Papers is one of the funniest books I've read, and good old Bleak House never lets you down, either, but I don't think you can go wrong with Dickens, personally.
But like other people here, I'd say no-one should be ashamed of what they've read or haven't read. By and large, the self-appointed arbiters of taste, in whatever field, are usually fools or charlatans.