Aside from using your drillhole data with any of the standard ioGAS plots and univariate/multivariate analysis tools there are two main tools that are designed specifically to be used with drillhole data. These are the 3D spatial plots and the Line Plot tool. The 3D spatial plot works just like the Attribute Map but for drillhole data which already has XYZ values for each sample interval in the dataset. You can apply colour/shape/size attributes to the downhole sample intervals and even export the attributed data in 3D DXF format to use in other mining programs.
The other tool which you may find useful for working with drillhole data as well is the Line Plot tool. This enables you to display each of your drillholes in a continuous line plot which can be stacked for easy comparison between holes. It is possible to attribute the line plot data points with other variables as well.