300TDI Leaky sump

Just did a transmission and engine service (all oils and filters) and noticed the slight one drip a night oil leak from my sump gasket has turned into 1/4 teaspoon a night leak!

What do you chaps use to seal the sump to the engine, I have heard rumours that gaskets dont exist and many use a sump silicon compound? what do you all recommend?
thanks again
Joe

generally either a gasket and don't kill it by over tightening or specifically motaquip hydrosil (aka sump sealant from peugeot dealers) far better than normal instant gasket