provbench
An early effort to catalog PROV benchmarks, which are datasets paired with queries and answers against those datasets.
See also https://github.com/provbench and https://sites.google.com/site/provbench/home/provbench-provenance-week-2014
The datasets in http://datahub.io/dataset?tags=provbench are also appropriate.
Issues about the maintenance of this collection is at https://github.com/provbench/meta/issues, documentation is at https://github.com/provbench/meta/wiki