my sister recently got one so has not tried much but she does talk about a chilli she has done, actually i think you may find info about it on this site - or even google slow cooker chilli recipie (sorry she is on hol so I cannot check). Another one she loves is a goulash from delias how to cheat. I think she commented it is a bit more expensive but she and her family loved that one too.
Not so much a recipe , but try doing your sunday roast in it .!
chop up a few vegetables , to place in the bottom of the cooker . place your meat on top of the veg , and cook for 8 - 10 hours on low . meat will be tender , and you can sieve veg and juices to make delicious gravy or sauce .