Here's a quick tutorial how to do a fresh install of the latest lts Node.js version on Ubuntu via Node version manager (nvm). This tutorial also covers removing any old Node.js installations. Installing via nvm is the recommended solution as you can manage different versions and root access is no longer required to install global node modules.

Removing all old Node.js versions and modules

Remove all node packages (note that npm should have automatically be removed but you can run the command just to be safe):

sudo apt-get remove nodejs
sudo apt-get remove npm

Cleanup node modules:

rm -rf ~/.npm
sudo rm -rf /usr/local/lib/node_modules/

You would now also need to delete any broken symlinks under /usr/local/bin/

Remove any existing nvm installation:

rm -rf ~/.nvm

Install nvm

Follow the installation instructions here: https://github.com/creationix/nvm

Install the latest lts Node.js

nvm help
nvm install --lts
nvm alias default node  # set the default version otherwise node is not available to a shell session

node --version # v4.4.7
npm --version # 2.15.8

And voila, you have a freshly minted version of Node.js :). Read on for more info on installing global modules and some useful npm commands.

Install global node modules

I personally need the following packages installed globally as well:

npm install -g grunt grunt-cli
npm install -g gulp
npm install -g mocha
npm install -g browserify
npm install -g envify

npm install -g clean-css uglifyjs nodemon node-sass
npm install -g forever

Useful npm commands

# List all installed packages
npm ls -g

# update a given package
npm update -g mocha

# find out all outdated packages
npm outdated -g