Which were the first 500 apps on the App Store when it launched in 2008?
This PinchMedia RSS feed in Wayback Machine is the best I could get so far:

Top 100 Paid Apps as of July 21, 2008

Still hoping I can get a full list. According to TechCrunch, there were 552 apps at the beginning, 417 paid, 135 free. If there would be a way to get top lists for all the categories, it should be possible to assemble the full list.