I don't wish to be contrary, but I go for Canon every time - unless it's wireless (not so in my situation). Canon works with Mac just-like-that, but I acknowledge issues users have had with wireless scanning.
Unfortunately I can't empathise with vansmith, whose contributions I respect, but my (now) old Canon MP110 just plugs on, and on, and on. The spare ink cartridges dry out unless I put them in the fridge. That said, I print b/w with a Brother laser, so the Canon doesn't get used all that much now - but it did for well over a year.
On the Canon subject...I just bought the Pixma MP 610 (from Apple) when I bought my MBP. I have only had both items less than a month & have already had 2 conversations with Canon regarding this printer & the numerous printing issues (I haven't even tried the scanning functionality yet).
Whether I am using my MBP, or if I am using a Windows maching running Vista, the printing issues are uniform. The printer acts fine when printing B&W, but when printing color, there are all sorts of lines in the document.
We (me on the phone with a Canon tech) ran through so many print head cleanings, alignments & tests that they had to send me new ink cartridges from draining the ink. Along with the new ink, they sent out a new print head. After replacing the print head, running through all of the alignments & tests again, to no avail, I am having the same issue with this printer. I am beyond frustrated with this thing.
I have always been an HP person but I was trying to avoid having to deal with HP's bloated software package that they insist the user install. It bogs down every machine that I have ever had to install it on, but at this point, at least the HP printed correctly.
I would like to give this Canon printer a chance to work correctly, but my patience are wearing thin. This has not been a good experience AT ALL with Canon.
If anyone has had any similar issues, I would welcome any advice you might have to help resolve.