If your a web designer and want to upgrade the look of a new or existing site, it can be done easily with the use of high-quality icons.  In this collection I’ve compiled the best and most high-quality icons and sets for you to use on your next design.  These awesome icons range from social networks to arrows.  There is always something out there that is a perfect fit for your website.  All of them are free, just double check with the source (usually stated on the download page) if it’s ok for personal and commercial use.

Twitter Icons

1. 6 Twitter Birds  on the Beach

2.  4 Hand Drawn Twitter Icons

3.  Birdies: Cute Free Twitter Icons for your Blog

4.  Blue Bird Twitter Icon Pack

5. 10 Free Twitter Icons

6.  Tweet Tweet Cute Tweet

7.  53 Brand New Twitter Icons

8.  Twitter Bird

9.  Free Twitter Bird Icons

10.  Free Twordle Bird

Facebook Icons

11.  Facebook Icon Shop

12.  Facebook Grunge Icon

13.  Facebook UI Vector Icons

14.  Facebook Icon Set

15.  Facebook Creature

RSS Icons

16.  Ojingogo RSS Icons

17.  Fresh, Free and Gorgeous RSS/Feed Icons

18.  RSS Feed Button Pack

19.  4 Glossy RSS Icons

20.  Seasonal RSS Icons

Business Icons

21.  Free Icons: Function Icon Set, 128 Completely Free Icons

22.  Business Icons

23.  Reality Icon Set

24.  Office Building

25.  Office Space Icons

26.  Office Men

27.  Office Women

28.  Office Web Icons

29.  Office Icon Set of 8

30.  256×256 Business Icons

Mac Icons

31. Aluminum MacBook Pro

32.  iMac 2008

33.  iMac and MacBook Pro

34.  iMac and MacBook Air

35.  Leopard iMac

Arrow Icon

36.  64 Arrow Icon Set for Developers

37.  Arrow Icons

38.  iChad PNG Arrow Pack 1

39.  Blue Arrow Icon

40.  56 Vector Arrow Symbols

Miscellaneous Icons

41.  Weather Vector Icon Pack

42.  Smashing Pumpkins: A Free Halloween Vector Pack

43.  Finance and Applications

44.  Milky, A Free Vector Icon Set

45.  ‘Primo’ Vector Icon Set

46.  Assorted Glass Buttons

47.  Cute Critters Icons Pack

48.  Random Icon Set

49.  Stick Pack

50.  Sticker Pack