Set Nemo as Default File Manager in Ubuntu/other Ubuntu derivatives

Nemo is a complete fork of Nautilus and its goal is to extend the Cinnamon user experience to desktop and file management. Nautilus has dropped type-ahead find search since 3.6 version and now using recursive search to find files/folders under current directory and sub-directories, most users don't like this behavior of Nautilus. Many of them started using other file managers instead of Nautilus.
If you already have Nemo installed or want to replace Nautilus with other File-Manager then Nemo can do a lot for you, install latest Nemo file manager from here.

After Nemo file manager installation, set Nemo as default File-Manager and allow desktop handling by Nemo open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

Terminal Commands:
xdg-mime default nemo.desktop inode/directory application/x-gnome-saved-search
gsettings set org.gnome.desktop.background show-desktop-icons false
gsettings set org.nemo.desktop show-desktop-icons true

Now enter this command in terminal to check that now Nemo is your default file manager.

Terminal Command:
xdg-mime default nemo.desktop inode/directory application/x-gnome-saved-search

Get back Nautilus as default File Manager with these commands:

Terminal Commands:
xdg-mime default nautilus*.desktop inode/directory application/x-gnome-saved-search
gsettings set org.nemo.desktop show-desktop-icons false
gsettings set org.gnome.desktop.background show-desktop-icons true

That's it
Thanks to steve for the tip