Uninstall programs/apps

Hi,
I was just wondering how to remove unwanted programs. I get an external hd tomorrow and want to do a fresh time machine backup or should i just do a complete factory reset?
I just want it like it was 2 days ago.

App cleaner will work or you can find the supporting files and delete them.
AppCleaner
or
How To Completely Uninstall Software under Mac OS X [MacRx] | Cult of Mac

Thanks

Words to live by:
If it came with an installer, use the uninstaller to remove it. Trust me on this.
If you drug it to the Applications folder from a .dmg, you can probably just drag it to the trash.