The Packet Clearing House (PCH) publishes BGP data collected at more than 100 internet exchange points (IXP). The snapshot dataset contains the state of the routing tables in daily intervals.
PCH also provides raw routing data in MRT format. These contain all the update information in sorted by time.
The RIS is the main resource from RIPE featuring all kinds of datasets about AS assignments and connectivity.
Routeviews is a project by the University of Oregon to provide live and historical BGP routing data.