3-D modeling and rendering comes to mind.
The Adobe Creative Suite will happily gobble it up.
My son has a virtual organ setup that requires 16 GB to load all the sound samples.
I have seen my own file server get bogged down when I transfer files larger than the amount of RAM it has, as it can not stuff the data onto the hard drives fast enough.
But, for 90+ % of the time, 1 GB is plenty for a VL machine doing "the usual" (surfing, e-mailing, playing media etc.).