I want the !! command to execute the last command I ran. Currently, when I hit enter, it just prints the last command I ran on a new terminal line, and I have to hit enter again. It worked with a single 'enter' press on a previous work station of mine, so I know it's possible.
For bash, the option histverify is probably on. Try shopt -u histverify, and see if you can begin to enjoy the immediate execution of previous commands again.