Browser/Plug-in

Pro: Though only available on Google Chrome, these easy-to-use wallets create and store your private keys on your computer and are always readily available.

Con: As with desktop clients, a web-based wallet is only as secure as the device on which your private key is stored. If the device becomes infected with malware, your key could be compromised.  Highly insecure.


* Examples and cost:

Myetherwallet: https://www.myetherwallet.com/ (Free)
MetaMask: https://metamask.io/ (Free)
Jaxx: https://jaxx.io/ (Free)