I've been using the Brother MFC-5440CN All in One Printer/Fax/Scanner/Copier for about 3 years now. I have found this unit to be very reliable. I use the machine every business day as I work from home and have only had one or two minor problems with it.
I use the print feature the most and print loads of stuff on it - it's not the fastest machine around for sure but for the money it does a great job. I've got it on a home network working for both a Mac and a Windows machine (a great feature). The only drawback to networking this unit is that is slows it down considerably. As long as you aren't expecting it to print the moment you press the print button it does just fine.
Ink cost is about average and it doesn't seem to waste much ink or run out too quickly.
Overall, I'd recommend this unit to anyone who has moderate printing needs.