Vectorportal (opens in new tab) contains a wealth of free vector art, which designers can use in both personal and commercial projects. It's easy to navigate, and you can filter your search using the drop down category box or search bar. With an extensive library of artwork, you're sure to find something of use here.
One of the largest artist communities on the web, DeviantArt (opens in new tab) is full of free and useful resources, including vectors. However, finding exactly what you're after in the crowd of chaos can be tricky. The search bar and Resources and Stock Images link will narrow things down for you, and no doubt you'll come across lots of free vector goodies.
15. Brands of the World
Brands of the World (opens in new tab) is an invaluable timesaver if you're designing for corporate clients and don't want to sit around waiting for someone to forward you a hi-res version of a certain logo. You can just find it here.
16. Spoon Graphics
Spoon Graphics (opens in new tab) is a personal blog belonging to designer Chris Spooner, which features a large number of well-made, original freebies. Come for the free vector art, stay for the excellent and insightful articles!
Popular site Vecteezy (opens in new tab) is a one-stop shop for any free vector art you can think of. Most of the designs are free, and although the quality does vary, it's worth rooting around as there are plenty of decent vector graphics to be found here.
VectorStock (opens in new tab)'s main business is a library of reasonably priced vector imagery, but as a handy aside it also boasts a substantial collection of free vectors. They're all available in EPS format, and it's nice and easy to create an account and start downloading.
19. Free Vector
With plenty of free vector sets available to download, you're in with a pretty good chance of finding what you want at Free Vector (opens in new tab). To make life easier there's a good selection of categories to choose from, plus a pretty sweet collection of company logos.