Fusion devices aren't rockets and are thus, not subject to the Tyranny of the rocket equation.
Orion gets its momentum transfer from the plasma debris of the nuclear explosion, and the plasma speed comes from the explosion itself. Orion carries the source of the plasma, hence it is limited by the rocket equation.
Basically any spacecraft that does not carry its own propellant. Most of these have either pathetic thrust or are way beyond our current state-of-the-art.
For instance, in a NERVA rocket, the "fuel" is the uranium rods in the reactor, the "propellant" is the liquid hydrogen that is heated and shot out the exhaust bell.