There are really only a few computer games that are appropriate for playing on a single computer with a bunch of friends. Of these, Gazillionaire is among the least boring. It's fun, interesting, educational, an competitive. Very similar to Trade Wars, Gaz is sort of like freeform Monopoly, set in space, with a complex economic model.
You play the owner of a brand-new shipping company in the solar system of Kukubia, competing against several other companies for the same trade goods and passengers. You own a ship, and make money by purchasing goods on one planet and transporting those goods to another planet, hopefully one where you can sell the goods at a good profit. You can also transport passengers.
Each turn, you are given the opportunity to purchase goods (that have to fit in your ship), pick up passengers, advertise your goods and passenger services, manage loans and bank accounts, pay taxes and wages for your crew members, buy insurance, and buy fuel. You can also visit the planet, find out about it's history, check the weather and news (for potential traveling hazards), and do something special on each planet. The planets and planet specials are:
Gazillionaire allows for a great deal of flexibility in the business model. You can set a high ticket price for passengers, but advertise a lot, hoping to get a full ship on the next planet. Planets go in and out of recessions and economic booms; the demand for products will be high on recessioned planets, while the supply will be high on booming planets. The goods you can trade in are, in order of price (in Kubars):
If you can sell a shipload of Exotic at a high profit margin, you've just made a killing, while dealing in Jelly Beans is almost pointless, unless you have a very big ship and there's nothing else worth buying.
Lots of things can happen to you while traveling between planets. Your ship can get raided by pirates. You can win the lottery. A starving artist can ask you to sponsor his new screenplay. The ghost of Quasi-Mutta can appear before you and demand that you reroute yourself directly to the holy planet of Mira or your luck will run out. Every so often there will be an auction of a larger ship or some planet's facility; the owner of such a facility will collect money from all the other players, Monopoly-style.
One of the things that makes Gaz great is its goofy atmosphere. The graphics are goofy, everything makes goofy little noises when you do it, and everything has a goofy name. It's just a goofy game.
Gazillionaire is available for Windows only, and was originally released for Win3.1. It appears to be written in Visual Basic, and an early version at that; all the graphics and sounds are on the root directory of the CD in .BMP and .WAV formats - a great sound effect library if you ever need one. Up to 6 players can compete on the same computer, and apparently there's some way of playing over a modem. Gazillionaire was made by LavaMind and published by Spectrum Holobyte.
There's a newer version of Gaz available, called Gazillionaire Deluxe. I haven't played it, but apparently it has a larger solar system, a more advanced economic model, and allows for customizable solar systems and net play. http://www.gazillionaire.com