I would say the Midwest includes the entire states of:

 

Ohio

Michigan

Indiana

Illinois

Wisconsin

Minnesota

Iowa

Kansas

Nebraska

North Dakota

South Dakota

 

and parts of:

 

Missouri (northern and central)

Montana (eastern 2/3)

Wyoming (eastern 1/4)

Colorado (east of Denver)

Kentucky (far north)

I agree with your first list, but I don't think that Colorado, Kentucky, Montana and Wyoming are Midwest.

Kentucky is the Southeast (to avoid a fight, never tell a true Kentuckian that it is a Northern or Midwestern state).

Montana and Wyoming are definitely the West.

I also consider Colorado (all of it) the West.

 

But then I looked it up just for fun.....

"The Midwestern United States (or Midwest) refers to the north-central states of the United States of America, specifically Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Ohio, Nebraska, North Dakota, South Dakota and Wisconsin."

http://en.wikipedia.org/wiki/Midwest

But then I looked it up just for fun.....

"The Midwestern United States (or Midwest) refers to the north-central states of the United States of America, specifically Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Ohio, Nebraska, North Dakota, South Dakota and Wisconsin."

http://en.wikipedia.org/wiki/Midwest

 

As a lifetime resident of the Midwest, that list sounds just about right to me. I have lived in MO, MI, IN, and am in the process now of moving to IA. Looking back, now, I need to spread out.