Can anyone recommend a good wi-fi all-in-one printer for Mountain Lion?

There are many good printers available. Choice depends on what you intend to print, how often, and what features you need. Do you plan to print documents? Do you need really sharp quality from a laser printer, or will an inkjet printer suffice? Do you need color output? Are you planning on printing photographs on photo paper? Do you need scanning/faxing/copying functions? What's your budget? So the answer to your question is not easy. You have to think about how you work and what you need.

For me, I've used HP printers for years for printing documents. I prefer the LaserJets for their superior print quality over the OfficeJet line. Right how, I have the HP Color LaserJet CP1525nw and the Color LaserJet MFP M175. The former is a wifi color laserjet printer that has excellent output, but it only prints documents. The latter is a wifi color laserjet as well, but in addition to printing, it also scans and copies (color and B/W). Both are compatible with Apple's Airprint so I can also use these to print from my iPad and iPhone.

For photos, I use an Epson photoprinter, the R1900. It only prints photos, but the quality will blow your mind.

Emma,

Yes, all of them are working with Mountain Lion on both my iMac and MacBook Air... both the 10.8.0 version and he 10.8.1 version that was launched yesterday.

FYI, Apple just yesterday added new printer drivers for HP printers, along with the ML update. This might be the reason that the reviews said some printers were not working with ML.

I'm not sure what the issue was with the Amazon reviews.... All I can tell you is that my gear all works with ML.

I really like the Canon Pixma series, myself. I've had both HP & Epson, but really love the Canons.

I am using HP Photosmart B110 on Mountain Lion with no apparents loss of features since 10.7.x to 10.8.

Airprint to iOS works too.

Here is a current list of multi-vendor printers supported by Apple in Mountain Lion. Got this description from this weeks HP Printer Drivers v2.11 for OS X.

I cannot recommend a multi-function because I do not use one myself. I did put together some screening ideas below for you that may help in your selection process.

Considerations:

1. Fits your long-term budget.
2. Simple to configure and use. Touch screen?
3. Do you need duplexing capability for printing, copying, and automatic document (ADF) scanning?
4. Multiple trays for different media?
5. Can scans or copies go directly to single and multi-page PDF?
6. Understand inkjet cartridge or laser toner advertised page count against your expected print volume.
7. Identify inkjet or laser toner costs before you buy, and as coefficients of your monthly usage model.
8. Beware printers that ship with starter inkjet or laser cartridges.
9. The previous customer comments are four or five stars.
10. If inkjet, does the printer offer a high capacity black tank separate from combined or separate color tanks?
11. If you use an iPhone or iPad, is the printer IOS AirPrint enabled? See also Printopia.
12. Ensure that the printer is fully OS X compatible and is supported above, or by manufacturer stated driver support for Lion or Mountain Lion.
13. Realise that included software bundles are typically out of date for OS X and may cause horrid application experiences.
14. Be aware that many printers that claim Mac compatiblity are sold on the basis of their Windows supported features and actual Mac functionality may subset expectations.
15. What are the priorities in printer usage. Document printing, scanning, copying, or faxing? If you print photos, what are your quality/size expectations?

the Color LaserJet MFP M175, but in addition to printing, it also scans and copies

Curious about the scanning, as I noticed a comment on the HP site "wishing the scan feature was easier to use." Can you scan from Photoshop and/or Preview or does it only use a proprietary piece of software? I've never owned HPs.

I'm using a Canon PIXMA MG5320 printer, think it was on sale for less than 99 bucks, and it is the quietest and best printer that I've ever had (and I've had laser printers). I just refilled all the colors of ink and it only cost me like 5 or 6 bucks for ALL of them combined from Amazon. The first time I ran the scanner it was so quick and so quiet that I didn't even know that it ran, and I was only around 6 feet away from it. I had a epson once but I will never buy another one because I found out that they have a sponge inside that collects ink every time you start it. I was wondering why ink was not lasting very long but now I see that they intentionally waste it, I guess because that's where they make their real money is on selling ink. I have had this new Canon printer now for around 4 or 5 months and it has worked flawlessly. Wish other things in life worked as good 🙂