Discord
All-in-one voice and text chat for gamers that's free, secure, and works on both your desktop and phone.
Stop paying for TeamSpeak servers and hassling with Skype. Simplify your life.
WhatsApp for PC is a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS.
Store and sync your email, calendar, contacts, files and documents in the cloud - yet have them locally accessible and aggregate information across accounts like Yahoo! Mail, Gmail, Hotmail and social networks like Facebook and Twitter
Instant access to The Pirate Bay, even if your provider does not allow you to visit it!
Thunderbird is email and calendar software by Mozilla (the maker of Firefox) that offers the same functionality as the (commercial) office application Microsoft Outlook.
Software bundle from Microsoft containing Mail, Messenger, Movie Maker, Photo Gallery, Writer, Toolbar and Family Safety.
Free calls to regular phones (+ mobile in US) over the internet
AresGalaxy is a Filesharing Bittorrent P2P client that works even behind firewalls.