An old standby for me is chicken wings. Just throw a bag in a crockpot with a bottle of either teriyaki or barbecue sauce.
A recent thing I've discovered is crock pot baked potatoes. Pierce each potatoe a few times. Wrap in foil. Cook on low 8-10 hours or high 2 1/2 - 4 hours. Set out some butter, grated cheese, sour cream and chives and you're all set.
I've never done baked potatoes in my crock pot but it sounds great. Do you need to put anything on the bottom of the bowl or do you just rest the potatoes in foil right on it? I just wasn't sure if the foil would burn but I guess it's not all that different than the liners that are out now?