Simulators typically place you in the present-day real world in charge of some type of machinery. Flight simulators are the most well-known type, but as you can see, there are many other simulators available.

BVE Trainsim:

As you might guess from the name, this simulator puts you in the engineer's seat of a passenger train. This simulator has a large following of layout designers who are constantly expanding the world that you can operate your train in. Version 4 is the latest stable version, with Version 5 (Vista compatible) to be released soon.

• BVE Trainsim site

 Dogfights: The Game:

This game recreates episodes from the popular History Channel show of the same name, allowing you to pilot fighter planes and pit different plane models against each other. Players begin with single-player training missions and then move up to online play against other pilots.

• Dogfights: The Game
  
  

Eastside Hockey Manager:

In Eastside Hockey Manager, you manage an ice hockey team and can pit your team against computer controlled opposing teams or set up an online league to play against others.

• EHM Download Site

Noctis:

Noctis is a non-violent space flight simulator where an imaginary galaxy is created, and you travel through the galaxy cataloging your findings.

• Noctis Download Site

Orbiter:

This is a space flight simulator which focuses on the physics and controls of navigating a space vehicle throughout our solar system.

• Orbiter Web Site

SimSig:

A train simulator from the point of view of a railway signaller. So realistic that it is now used as training for railroad signallers.

• SimSig Download Page

Simutrans:

Build a city-wide transportation company and respond to problems as they arise.

• Simutrans Sourceforge Page

SpaceCombat:

A space combat simulator with realistic physics and detailed 3d graphics.

• Space Combat Home Page

TORCS:

A popular modern racing simulator available for many computing platforms, with advanced graphics.

• TORCS Sourceforge Site

Volleyball Manager:

A series of Volleyball Management Simulations.

• Volleyball Manager Site

YS Flight Simulator:

This free flight simulator features both non-violent and combat modes depending on which aircraft you choose to fly. Graphics are not up to par with other modern simulators but aircraft controls are realistic.

• YS Flight Simulator Download Page