Git and Mercurial have powerfull command line interfaces besides GUIs like TortoiseGit, GitExtensions and TortoiseHg.
There are two projects that I like Posh-Git and Posh-Hg. These projects add to the Powersherll terminal TAB completion and some usefull information in the prompt as shown here:

The problem that I had is that even if it is well documented how to install each one, I couldn't make both work in the same machine. There is an answer in stackoverflow which is a very good starting point, but it has a problem with the path variables used and TAB completion in mercurial seems broken after.
This is how I installed and I have both working now. First you will need to download the two repositorios to My Documents\WindowsPowerShell\Modules\ and then in My Documents\WindowsPowerShell add a file named profile.ps1 with the following content:
function isCurrentDirectoryARepository($type) {
if ((Test-Path $type) -eq $TRUE) {
return $TRUE
}
# Test within parent dirs
$checkIn = (Get-Item .).parent
while ($checkIn -ne $NULL) {
$pathToTest = $checkIn.fullname + '/' + $type;
if ((Test-Path $pathToTest) -eq $TRUE) {
return $TRUE
} else {
$checkIn = $checkIn.parent
}
}
return $FALSE
}
# Posh-Hg and Posh-git prompt
. $Home\Documents\WindowsPowerShell\Modules\posh-git\profile.example.ps1
. $Home\Documents\WindowsPowerShell\Modules\posh-hg\profile.example.ps1
function prompt(){
# Reset color, which can be messed up by Enable-GitColors
$Host.UI.RawUI.ForegroundColor = $GitPromptSettings.DefaultForegroundColor
Write-Host($pwd) -nonewline
if (isCurrentDirectoryARepository(".git")) {
# Git Prompt
$Global:GitStatus = Get-GitStatus
Write-GitStatus $GitStatus
} elseif (isCurrentDirectoryARepository(".hg")) {
# Mercurial Prompt
$Global:HgStatus = Get-HgStatus
Write-HgStatus $HgStatus
}
return "> "
}