When I don't feel like washing and roasting fresh veggies (which is often), I opt for the frozen kind. They are bagged at peak freshness so you never have to worry about them going bad. Plus, they are much more affordable than fresh, and you can buy them in bulk. I currently stock up on 365 Everyday Value Organic Broccoli Florets ($3) and 365 Everyday Value Petite Brussels Sprouts ($1).
I usually add these to stir-fries, heat them up in the microwave, or heat them up and then pop them in the oven. I can also throw these in my rice cooker steamer basket.