My 2006 colbalt

head lights nice and bright ? batt terminals are tight ? could be the stater , is there a starter relay ? see if power is getting to the starter when you hit the key you have to nearly remove it to do that you mat want to replace it

You may be experiencing a failed security system. The security system is notoriously known to fail. Basically when you insert your key, the system checks for a certain signal. If the system cannot get the correct signal from the key, it assumes the key is incorrect or you are attempting to hotwire it. The system then goes into SECURITY lockout mode. (prevents vehicle theft) This will either turn off the starter, or the fuel injectors. This has been happening with GM's for a very long time. There are ways to bypass this now. Read through this page for info, solutions as well. http://www.diy-gm-security.com/