I like stuffing my ravioli with a mixture of butternut squash and ricotta, with a little bit of sage. It doesn't need a heavy sauce, so I usually just saute it in butter (I add some more sage) and a little bit of chicken stock.
I've also experimented with a crawfish stuffing - I put crawfish, onions, and some red and green peppers into
i do the same w/ butternut squash, but i'll add a little jarlsberg or gruyere to the mix.
also love a mince of wild mushrooms (portabello, cremini, shiitake, oyster) and caramelized onions and a bit of thyme; i usually make a walnut pesto to go over it
sometimes simply ricotta mixed w/ oregano and basil but topped w/ chopped tomatoes, julienned sundried tomatoes, basil shreds, oregano, parmesan cheese, olive oil, and seasoned rice wine vinegar. i might add eggplant to this filling.
crab or lobster claw meat also makes an excellent filling.
In our italian family we made ravioli stuffed with either hamburger, spinach and parm or riccota, parmesan and egg. Both ways are delicious. we would serve them with homemade tomato sauce that my noni taught us how to make. She made so many wonderful homemade pasta dishes that it is hard to buy from the frozen food section. Another idea would be butternut squash ravioli served with a brown butter sage sauce. You can pretty much stuff them with any of your fav ingredients. Happy cooking!