The only game where I've seen real-style hacking is Enter the Matrix. That used basic hacking techniques that, although now outdated, were accurate of the way people could hack computers at the time. A lot of hacking, however, is just stealing passwords and so on. You could probably gain access to military databases through a backdoor in the system with a simple internet connection and knowing an officer's login details. Makes you think how scary that would be, if that's what the security is really like on our national computer databases...