HP 2550L - Good all round printer if not a bit bulky for the home office.
I use one at work and at home - I wouldn't recommend getting the additional tray for paper, you are better off using the sheet feeder, it tends to confuse it - Tempramental things printers!
Apart from the obvious additional costs in replacing the print toners and drum I think it is good value for money.
Shop around for replacement toners though I've been quoted anything from £311 - £120 to replace the lot.
Print quality is good and it prints documents quickly.
You can double side print, it will print alternate pages then ask you to reinsert the paper to print the rest.
HP toolbox is easy to use and you can keep an accurate check on your ink levels.
I'm sure it has lots of additional features but to be honest if you've got the time to play around with all these things you either need to get out a bit more or get a job!