TUTORIAL: Bypass the Launcher

To start your game directly without using the launcher, go to the following folder

Since Generations/1.22 you start the game from this file:
[Installlation directory]\Game\Bin\TS3W.exe

That's probably the file you are going to start the game from now on, so you don't need to worry about changing the file with every EP anymore.

 
If you are not patched to 1.22 or higher, use this files:
Base Game: [Installlation directory]\Game\Bin\TS3.exe
World Adventure: [Installlation directory]\Game\Bin\TS3EP01.exe
High End Loft Stuff: [Installlation directory]\Game\Bin\TS3SP01.exe
Ambitions: [Installlation directory]\Game\Bin\TS3EP02.exe
Fast Lane: [Installlation directory]\Game\Bin\TS3SP02.exe
Late Night: [Installlation directory]\Game\Bin\TS3EP03.exe
Outdoor Living Stuff: [Installlation directory]\Game\Bin\TS3SP03.exe

and double-click on the .exe file. You can also make a shortcut on your desktop.

Further Reading

• Game Help:TS3 Bypassing the Launcher 
• EA Support Page