When Is a Suburb Not a Suburb?

Seattlest, the blog about Seattle, faces the question: Is a suburb that is no longer dependent economically on its city, that has broken the 100,000 population mark and is the fifth largest city in the state, still a suburb?

The debate about Bellvue originated on Wikipedia, which gives this list of suburban communities with at least 100,000 residents.

Mesa, Arizona (Phoenix)
Elk Grove, California (Sacramento)
Henderson, Nevada (Las Vegas)
Paradise, Nevada (Las Vegas)
North Las Vegas, Nevada (Las Vegas)
Hialeah, Florida (Miami)
Aurora, Colorado (Denver)
Lakewood, Colorado (Denver)