The Rhone is split into two - the north and the south. The North is Syrah and Viognier territory and the south is Grenache, Syrah and Mourvedre focused, and throughout you have Roussanne and Marsanne being undiscovered white wine gems.
Aside from the lovely every day drinking Cotes du Rhone wines, do give the wines from Saint-Joseph, Crozes-Hermitage and Cornas a go (they are from the North) and if you fancy alternatives to Chateauneuf-du-Pape, have a bash at Rasteau, Gigondas and Vacqueyras - all in the southern Rhone.