Drosophila medulla full connectome
Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.
This is the drosophila medulla connectome (directed graph, Pajek format) built from the supplementary table 1 from http://www.nature.com/nature/journal/v500/n7461/full/nature12450.html
379 Nodes (neurons), 3193 links, connection strenghts are the number of synapses per neuron pair.
I will post the code (bash script) I used to generate the connectome later so that people can double check.