We bought a Brother HL-5250DN laser printer. We were getting sick of ridiculously pricey inkjet printer supplies, cartridges that expire while still 3/4 full, print heads that fail after 1% of their expected life, cartridges that read completely empty while still 3/4 full, and flakey printing that can be brought back to life by cleaning everything out with Q-tips and tissues. So the inkjet is going to be reserved for color work only, particularly photographs. When it dies I think we will probably not get another inkjet, although I have been considering a dye-sub printer specifically for high-quality photo printing.
My mom has an HL-5240 and it has been working very well for her -- much better than her own inkjet, which was constantly clogging up due to lack of regular use. This one is working very well for us. We got it for $250 with a $50 rebate.
So far I would recommend this particular model highly! I have printed out several book-length double-sided documents and then had them bound. The binding is a fraction of the cost of having the whole things printed and bound at a copy shop like OfficeMax. It means Grace can do some a lot more of her work from home without having to get two babies into car seats for a car trip just to print a couple of pages.
The HL-5250DN comes with 32 megabytes of RAM and instructions on where to get and how to install a RAM upgrade. Although my impulise is to get a DIMM and max out the RAM, the manual is completely silent about is why we might want or need a RAM upgrade. It implies that lots of fonts or very complicated images might require more RAM, but in practice I can print my PDF books full of diagrams and formulas, or even full-page color photos (reduced to grayscale) without any problems, so I have to stifle that impulse.
It is a 3-interface printer: parallel, USB, and Ethernet. Right now it is actually downstairs, connected to our little Airport Express via USB, which is joined to the wireless network. Rendezvous discovers it flawlessly and allows computers on the network to print. I suppose that means our neighbors could print to it as well, but so far that has not been a problem, and I don't believe in restricting things that don't demonstrably need restricting.
The CUPS PPD for the printer was easy to install on MacOS X 10.3. (10.4 might come with a PPD for this model; I haven't tried it yet). Without the right PPD you can print, using a generic printer specification, but can't print double-sided.
We could have gone for a color laser, but I don't think we have a genuine need for it. I eventually want to add a scanner. I really want it to do only two things: scan full (borderless) letter-sized pages with good resolution, and scan negatives. I have a big backlog of negatives to scan. It could in fact be more economical to have a service bureau scan the negatives, but I have not determined that yet. It's a project for a day when I have more free time and more money. I'm way, way behind the curve, and actually prefer to be there -- it is a lot cheaper! I guess that makes me old!