1) Christian Computer Art http://www.cc-art.com/ . A whole variety of cartoons, diagrams and other teaching aids. Incldes the line drawings from the Good News Bible. Getting slightly dated, but certainly worth a browse. Quite a lot is for free. The £14 life-time fee allows fuller access.
2) Zionworx http://www.zionworx.org.uk/ This is a worship presentation package, like Easy Worship. They have a few high-quality images for use - the usual uplifting sunsets and scenic views.
3) Igniter Media http://www.ignitermedia.com/ Huge variety of images, movie clips, songs, ready-made sermons, etc. Rather American. Will take a lot of further browsing for a proper evaluation.
4) Run http://www.run.org.uk:80/R/resource/video.aspx Powerpoints, videos, drama scripts and more. Most of the videos are English rather than American. £44 to join. ( It offers some free downloads, but I couldn't find any.)
5) Worship House Media http://www.worshiphousemedia.com/ Another large collection of videos, tracks, images etc etc. Rather American - there's a lot about the 4th of July as a religious celebration - but worth looking through.
And Finally (For Now)...
Collide Magazine has produced a "Top Ten" review of providers at http://www.collidemagazine.com/article/47/the-top-producers-of-church-media . A rather better version of what I'm doing here!