With my personal experience of what I am using right now is Trillian and this also works like a email client.*And in my opinion this is even better than Google talk
I will list down some features from its official website and few screenshots
for your reference.
This is available as gratis and paid
- Continuous Client
Your chats go with you everywhere. Trillian even keeps your phone quiet when you're active at a desktop!
With support for Google Talk, Facebook, MSN, AIM, ICQ, Yahoo!, and more, stay connected with everyone.
- Device Support
Trillian is available on Windows, Mac, iPhone, iPad, Android, BlackBerry, and directly in your web browser.
POP3, IMAP, and native IM mail integration. New mail alerts and basic mail management are all exposed.
Never miss a beat with Trillian's social integration, keeping you connected to Facebook, Twitter, and LinkedIn.
- Tabbed Chats
Keep your desktop tidy with tabbed chats, featuring drag and drop support, unread indicators, and more.
- Message History
All desktop versions of Trillian come with a fully-featured message history viewer, including searching and filters.
Trillian's integrated spellcheck will always let you know when a word is misspelled and offer suggested fixes.
Hundreds of amazing handcrafted emoticons for your chatting pleasure. Find them all, even the hidden ones!
User-created language packs and strong UTF-8 support help ensure a great experience in your native language.
Note: To use any version of Trillian you'll have to have your own Trillian Account (formerly "Astra Account"), which keeps your settings synchronized between Trillian on your desktop, mobile devices and in-browser Trillian for Web which also another feature.
Hope my answer will help you to get out of Hangouts Chrome App ;)