Whats the best way to remove a program?

For instance, lets say I want to remove The Sims 2 and all of the expansion packs, what would be the best way to do this? On certain things I have drug the icon to the trash and deleted it that way but in my Finder search I can still pull up items associated with that program, HELP PLEASE!

You can try a freeware program called "AppCleaner". It does a pretty good job finding plist files, etc. There are other freeware and commercial products that uninstall apps.