Simulation games are...
By definition a simulation is an imitation. So simulation games are games that imitate a real-life situation. Another way to think about it is that simulation games attempt to recreate a past event. But games don't always stick to that definition, sometimes they border on fantasy or potential future situations.
Within the simulation games genre there are sub-genres. Because of the variety of simulation games, there is probably at least one sub-genre that you may enjoy, whether it be flight simulation games or life.
Life Simulation Games
Life simulations directly imitate life itself, whether it be daily life or playing god. This is a great genre that has grown drastically over the last few years. Popular games of this type include "The Sims 2" and "Black and White 2."
Business Simulation Games
This section covers a lot of area, including games that are also included in the city building category. Business games deal with economical situations, and managing your own business.
City Building Simulation Games
In city building games, you design the layout, make laws, collect taxes, and try to build your city. Gameplay varies from different game to game, but the premise is the same, to develop a successful city.
Flight Simulation Games
Flight sims give you the chance to be a pilot of just about any plane or helicopter you've wanted to fly. The genre of flight simulations has come so far over the last few years. The graphics are intense, many playing options, and realism keep flight sim fans going back for more.
If one type of simulation game doesn't work out, try another. I don't like all types of simulations equally. You may love a good tycoon game, but not get into life simulations. Nothing wrong with that.