Try Screenshot. It comes with more advanced option than the Print Screen button. You can find it by searching "Screenshot" in the Dash.
Another more detailed Screenshot tool
Shutter
It has a plugin support and some image filters
Install it by ppa
You can add a PPA to your system with the following procedure.
Open a terminal and enter:
sudo add-apt-repository ppa:shutter/ppa
Now, as a one-off, you should tell your system to pull down the latest list of software from each archive it knows about, including the PPA you just added:
sudo apt-get update
Install Shutter
sudo apt-get install shutter
PRINT SCREEN
key.