From Andy M: Oh the memories of reading, and re-reading Radclyffe Hall's The Well of Loneliness. Actually - the first 3rd, a fairly trad., Victorian 'country house' Bildungsroman is almost readable. It gets worse though - Id say to the point of unreadability, but it has the same sort of fascination that road crashes or surgical documentaries have. Someone was going to write the first lesbian campaigning novel; pity it's Hall. Well meaning in its day, but truly truly grotesque! Go read it.. .
Also: Arnold Bennett's The Old Wive's Tale: forced to read it by a stodgy, gout-suffering lecturer while I was at university: totally loved it! Its got - in a long segment - an entirely gripping account of the impact of the Siege of Paris.
Is it worth pondering on the 'why' of 'forgotten classics' as well as the 'what'? In Bennett's case (and vanloads of other popular late 19thC / Edwardian writers) it is the academy's obsession with so-called literary modernism (and that opens a can of class-based elitist worms!).