by "old" literature I assume you mean classics - how can you not care about them? I mean, you appreciate modern literature to the fullist extent without reading the classics. All writers, whether they like to admit it or not, are influenced by what they read, and then some parts of it, conciously or not, get into their own writing.
I actually like Purloined letter more...but you really can't beat the first sentece of Usher - it is one of the best opening sentences in gothic literary history.