Links to the best places to get free GIS data, in Australia anyway!

Australia

Queensland Data – https://qldspatial.information.qld.gov.au –
Various Raster and Vector data for queensland
Department of Natural Resource and Mines – https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0008/199979/gis-datasets-locations.pdf –
Really useful PDF showing a Index of tiles of the whole of queensland
ELVIS Portal (Australian 1 Second Arc 5m DEM) – http://www.ga.gov.au/elvis/
You can download small portions of this SRTM derived DEM using this nifty little tool provided by Geosciences Australia. (Australian Only)

Elevation Data

SRTM – http://dwtkns.com/srtm/ –
Click and bang for Shuttle Radar Data.
NEDF – http://nedf.ga.gov.au/geoportal/catalog/main/home.page –
You will need to register, but this dataset contains SRTM-derived 1-sec ARC tiles that are a lot better than the SRTM stuff above.
Geosciences Australia – 5m Lidar Tiles – http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_89644 –
Has it all but these are huge files >10G B
FSDF (ANZLIC) – http://elevation.fsdf.org.au/
Incredible quality, full point clouds publicly available.

Geology and Groundwater
Groundwater Boreholes – http://www.bom.gov.au/water/groundwater/explorer/map.shtml
Very useful link to download “registered” borehole monitoring data. Including lithological and hydro-geological log data.

Geofabric – http://geofabric.bom.gov.au/documentation/
Either Stream the WFS or WMS layers straight in form this link. Contains Groundwater Aquifer Contours etc. or download the whole thing here, from the ftp site