Cooking vegetables

We all know veggies have lots of nutrients, but so many people cook all the good stuff out. Basically if your water changes color those are the nutrients. So how do we cook them, and not lose too many? Microwave is great, except cauliflower, steam, and then shock until just tender, roasting works well for many also, and adds some flavor. Boiling should be a last resort, but is really convenient. Remember most veggies when cooked should still be fairly crisp, and never limp.