A plasma rocket wouldn't work.
sure the thrust would be huge, but since it breaks ALL matter down into its' constituent elements there wouldn't be much left of the launchpad, would there?
Fusion generators dont work because the magnetic field is;
A) Too Low powered
B) Cannot contain the plasma if it 'punctures' a certain point..I.E, if there is a pressure inconsistency the plasma will fly out of the field and rupture any matter-based containment device until it cools down.
The way to get around B is having the plasma circle around in a torus shape (this is what a tokamak is, kids) - this gets rid of SOME of the pressure differences.
To get around A though you need to have a large energy input to actually have a powerful enough magnetic field to contain the plasma (which you have to get from heating hydrogen gas to >14million degrees kelvin)
Basically until someone comes up with superstrong magnets and something on the level of a miniaturised nuke to get the gas to fuse, fusion will be relegated to small scale laboratory testing

------------------
Remember, when someone annoys you it takes 42 muscles in your face to frown, but it only takes 4 muscles to extend your arm and ***** slap them upside the head.