File Browser Is my pick because...
Not only can you stream videos from your pc you can download the video file to the iPad. You can download any file type from your computer to the iPad, photos, text files, keynote, pages, PDFs, etc...etc...etc... You can upload the same files from the iPad to your desktop computer.
When you place videos into a folder within File Brower the videos will play one after another like a video playlist...
Just like Air Video you can setup File Browser to play videos from anywhere that you have a wifi connection. (I suppose you could do the same with a 3G connection too.)
One last thing... Air Video is a little faster streaming videos. But, you need Install Air Video on you desktop computer along with the app on the iPad. FileBrowser does need to be on the desktop computer just on the iPad. I use both and I am satisfied with both apps.
I am assuming that with Filebrowser you can play itunes purchased content on the ipad, correct? It streams the file to the ipad, but the IPad video player sees the file as if it were already loaded on the ipad, correct?
If this is true (?) this is clearly a big advantage of Filebrowser over Airvideo for those who have DRM'd/itunes purchased video content.
Here's another vote for Zumocast - works great and it's free! Easy to install and works great even on older slower PCs. Video player does not handle chapter breaks but I can't complain. This app turns your PC/Mac into a cloud server, enabling you to access your files and play your videos on your iPad/iPhone/computer from anywhere you have an Internet connection. This is very cool, and I didn't need to change my firewall configuration.