Grenache is one of the most widely planted grape varieties in the world. It is responsible for some of the most famous wines around and most people don't even know the name as it is widely blended to make those famous wines. I read somewhere the other day that Grenache is as important in the wine world as Cabernet Sauvignon - and i'd whole-heartedly agree.
If you have ever heard of or drank Chateau Neuf du Pape then you will have heard of or drank Grenache.
Grenache is typically blended with Shiraz, Carignan, Mourvedre, Tempranillo and Cinsault and is at home in hot climates.
100% grenache wines are available although most have a small % of other wine added to soften the tannin.
There's even a day named after Grenache - Grenache Day - check it out.