1. 170 Free Web Icons from WooThemes by 32×32 PNG’s
There are nearly 170 free web icons in 32×32 PNG format that is designed by Janik Baumgartner and published under GNU General Public License.
You can download it from here: 170 Free Web Icons.
2. 21 Free Icons for Tumblr icons
You can download it from here: Free Icons for Tumblr.
3. Bold Social Media Icons (Both the PNG’s & PSD files are included)
Download it here from here: Social Media Icons.
4. 178 Amazing Web Design Icons
You can download it from here: Web Design Icons.
5. 42 Social Media Icon Set in 64×64 (Both PNG and PSD form)
You can download it from here: 42 Social Media Icon Set.