Elite
"Elite" was written by David Braben and Ian Bell starting in 1982 while the authors were still at Cambridge University. It was first published by Acornsoft on the BBC Micro in September 1984 to huge critical acclaim. The rights to other computer platforms were then auctioned by Jacqui Lyons of Marjacq, and British Telecom then went on to publish on many other platforms under the name of Firebird.
In "Elite" the player starts with a basic Cobra MkIII space craft, and a measly 100 Credits. The player then has to survive in a hostile galaxy containing traders, pirates, police, bounty hunters, and an elusive alien race, the "Thargoids". The player can earn money in many ways, including taking say, food from an agricultural world to an industrial world, and machinery on the return journey. They may prefer to be a pirate themselves, or perhaps do a little of each.
"Elite" set many firsts, and was the first genuine 3D game on home computers. Even many years after its release it is fondly remembered. For example "Probably the best computer game ever" (The Times, December 1988). It went on to sell around 1,000,000 units, and is popular still, having appeared on most popular formats.