Butler's Erewhon was published in 1872...the Swift in 1726, amended in 1735. For my money, they should both be included in the canon. I include Frankenstein also. Pym is marginal, but why not? Certainly it influenced At The Mountains of Madness, which is closer to the spirit of sf, and that in turn likely influenced Campbell's Who Goes There?, which is certainly science fiction. It depends on whose opinions you want to subscribe to...Trillion Year Spree is a good read even if you're not into sf, as Aldiss is an extremely good writer. The Swedish writer Sam Lundwall has also published histories of sf which are very good. Here's a discussion that mentions some other originators, such as Lucian of Samosata and Arioso:
sf origins...others may consider the Bible or even the Epic of Gilgamesh as the progenitors, though those are more fantasy-oriented in my opinion.
As far as detective fiction, the Gold Bug is generally considered to be the first example of "modern" detective work. Here's a discussion of the origins of detective fiction:
classic crime fiction...in which Zadig is mentioned, as well as the memoirs of EF Vidocq, who was the head of the French Surete. No mention of Puddnhead though. Surely that's an oversight.
