+1 for glass being a non starter for me. I have a couple of these and really like them: http://morebeer.com/products/speidel-plastic-fermenter-30l-79-gal.html.
Large enough so I've never needed a blow off tube, easy to clean, has a port to easily rack and the integrated handles are sturdy and great for moving around 5 gallons of wort.
Thing that scares me about that I guess is the spigot, which are so hard to keep clean on plastic and when you take them apart to clean they never go back together properly and leak. Maybe this one is constructed differently.
That was the exact issue I had when I was thinking about buying these. The spigots are made much better than the normal ones you see on buckets or better bottles and the parts are larger. However, I still worry about these spigots when it comes to sanitation.
The spigots are optional as they come with a cap that you can put on instead of the spigot.
These things aren't perfect, but so far I like really like them. Here's a few "issues" I've found:
It took me a couple of tries w/ different tubing to find the best tube for the spigot and I found 3/8 inch silicon tubing works the best.
All of my transfers have a little yeast w/ the first pour.
The airlock is big and doesn't show the activity as a regular airlock, but it works well.
Overall these are great fermenters. My beer tastes the same as they did w/ carboys and buckets, but the cleaning, transferring and moving are much easier. As Keith mentioned above, if you use the spigot, just have to take extra precautions to keep it sanitary.