At work, I use Win7 and the Snipping Tool, usually to select an area --- it works well. In the past I would use PrintScreen --- and I also learnt that Alt-PrintScreen would copy just the active window, so you don't have to crop it.
At home Linux Mint has a ScreenShot utility that can grab the whole screen, current window, select an area, with or without pointer, and with a time delay..... but I don't use it much as home.