Compared to bag oats, not always. Many packet oatmeals have lots of added salt and sugar. Sometimes the oats are quite processed too, so you don't get as much fibre as from the bag oats.
There are a variety of oats out there from quick oats all the way to steel cut oats. The difference is really in how long it will take you to cook them. Some of the longer cooking oats will have more protein and fibre (again, because they are less processed). However, quick plain oats from the bag can still be a healthy choice, not to mention save you time.
Here are some ways to improve the nutrition of any oatmeal:
-Add fresh fruit on top for a great antioxidant kick
-Add extra fibre with things like ground flax seed or wheat bran
-Mix in a little protein to help you feel full by using almonds or walnuts
-Avoid adding too much sugar or syrup...again, fruit (fresh or dried) will add plenty of sweetness.