A great bolognese sauce starts with three sorts of meat (pork, veal, beef), which will be cooked into red wine sauce. Add some carrots, onions, celeri, some olive oil, and fresh tomatoes, and let it simmer for a couple hours, so that the meat and veggies fully soak into that sauce.
Obviously, the bolognese sauce is going to be more important than the spaghetti, so we are going to need a wine which presents rather powerful features: tannins need to counter the fat of olive oil.
If you wish to stay Italian, you can try a Chianti which gives hints of cherries, plum and sage.
For a French wine, I would recommend a Rhone valley wine which contains a dominant of grenache.
