1. Of course all zone one is better. Usually when you buy at FS or BB, it's Zone 1. You can try to google to find how to unlock to all zone.
2. If you have downloaded some movies, having usb port is good to have.
3. Try to see how many computer formats that dvd player can read.
4. Output port.
I will pick good brand name one and wait for it to be on sale.