One of the best roasted veggies is just carrots, stuffed under your chicken, beef, (or pork) roast. They come out all soft and caramelized-sweet. My favorite way with carrots.
Every time I roast chicken I throw potatoes and veggies under the roasting rack. You HAVE TO. You cannot roast too many onions either. It is just too good. Roasted in the chicken drips..... heaven.