Their sausage biscuits are great. Same for the McGriddles. Breakfast burrito is also good and cheap. Love, love, love the Mac, but it's so unhealthy that my heart can't manage more than one a year. Mocha frappe is delicious! Fries are good, but really they're just a method to get to the ketchup. Their ketchup could be a meal by itself. I've always wondered if it was specially crafted just for McD's.
You'll never find a better Diet Coke than fresh from a McDonald's dispenser. I read an article a few months ago about why that's true, kind of interesting.
With all that said, I still think Wendy's single is the best tasting fast food burger, and BK's whopper jr. a close second. But McD's has the winning combination of being cheap and fast, something the others just don't have.