Well, ok, Consolas wasn't specifically designed for PowerShell but rather as an enhancement for all consoles. It is a new Microsoft font that really looks cool and enhances readability with special support for ClearType and flat screens. And it's free, get it here: http://www.microsoft.com/DOWNLOADS/details.aspx?familyid=22E69AE4-7E40-4807-8A86-B3D36FAB68D3&displaylang=en
Once you have downloaded and installed the font, you need to make sure it can be selected by the console property dialog. All fonts that you want to use inside of the console need to be (a) monospaced and (b) registered in the Windows Registry in this key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont
Simply add a new REG_SZ-Value and name it "00000" (just add as many zeroes to the name as are necessary to make it unique). Assign the font name to this entry, for example "Consolas". Next, reboot your machine. Once restarted, the newly registered fonts can be selected from inside the console properties dialog.