A list of Challengers from wikipedia.org follows. The steam locomotive version is actually a class of locomotives used by the Union Pacific Railroad, of which one (#3985) is still used to this day for excursions and is the largest operable steam locomotive in the world.

Challenger a brand of AGCO
HMS Challenger, any of eight Royal Navy ships,
Challenger (clipper), a clipper sailing ship
Challenger (passenger train), a named passenger train fleet
British Army tanks:
Cruiser Mk VIII Challenger in service during World War II.
Challenger 1 in service from the late 1980s to early 21st century
Challenger 2 in service from 1998
Canadair Challenger, a series of business jets manufactured by Bombardier
Dodge Challenger, Dodge's entry to the pony-car market
Mitsubishi Challenger, an SUV sold in export markets as the Pajero Sport/Montero Sport
Space Shuttle Challenger, which broke up shortly after liftoff of its tenth mission, in 1986. (See Space Shuttle Challenger disaster for information on the disaster).
a ferry Stena Challenger formerly Isle of Inishfree and Pride of Cherbourg, now the MV Kaitaki,
4-6-6-4 steam locomotive wheel arrangement
Challenger, the Apollo 17 lunar module
Quad City Challenger ultralight airplane