Your comment jogged my memory. Ulysses, a cleverly-named solar-polar mission, used a deployment from the Shuttle, and a gravity assist from Jupiter, to reach an inclination of 80 degrees.
> Because direct injection into a solar polar orbit from the Earth is not feasible, a gravity-assist is required to achieve a high-inclination orbit. As a result, Ulysses was launched at high speed towards Jupiter in October 1990, after being carried into low-Earth orbit by the space shuttle Discovery. Following the fly-by of Jupiter in February 1992 /3/, the spacecraft is now travelling in an elliptical, Sun-centred orbit inclined at 80.2 degrees to the solar equator.
On that matter, are there any significant objects (natural or artificial) orbiting way outside the plane of the solar system?