My 40k models have usually been done to 'tabletop standard', as I just can't dedicate the time to a whole army. That said, I still get distracted and end up trying to do fancy things like mass convert metal Kasrkin, or press mould Inquisition symbols for ex Imperial Guard Chimeras.
There was once a whole Grey Knight contingent, but sadly, no evidence remains of this mysterious chapter, except for a sole dreadnought.