MultiBit

MultiBit is a secure, lightweight, international Bitcoin wallet for Windows, MacOS and Linux.
Features:

Quick and easy to install across all major desktop operating systems (Windows, Mac, Linux)
Secure by design - all private keys are kept encrypted on your local machine (or on a USB stick)
Faster to synchronize - usually a minute or so
Lighter - the stored data is much smaller (usually a few megabytes)
Flexible - multiple wallets allow for a "current account", "savings account", "expenses" etc
International - multiple languages (35+ at the last release)

If you are an ordinary user of Bitcoin and simply want a wallet that just works without hassle, then MultiBit is the right choice for you.

BTC Vault