I'm using a Canon MP620, which offers wireless scanning and printing, and has 5 ink tanks (CMYK + large-capacity black for text and B&W images). I've been completely satisfied with it--the wireless printing and scanning works flawlessly to all my Macs, the quality is very good, it was quite inexpensive, and as with all Canon printers it's relatively thrifty with ink. You also don't have to replace the tanks until you want to--it warns you that they're getting empty, but will continue printing until and after no ink comes out of that color at all (which is a big step up from at least some printers, which will force tank replacement when the chip says its empty, whether there's ink left in it or not).
The current version of that MFC is the MP640, which has similar specs but adds auto-duplexing. The MG6120 appears to be almost identical, including price, except it adds a grey ink tank. There's also the higher-end MP990 and MG8120; not sure what the advantage of either of those is apart from adding film scanning, but they're more expensive so presumably have some increase in quality.
I have only ever had a single issue with the device: If you're scanning something that includes the color neon pink, it will come out looking undersaturated. I've only ever seen this in practice when scanning a CD cover that has hot pink cel art on it--it's never been visible in any photo scan, or anything else. I also saw exactly the same behavior from the scanner in a Brother multifunction device, so it's obviously a more widespread problem, although not universal, as an older Epson scanner didn't show the issue.
That's an extremely minor complaint, however, and nowhere near enough to make me recommend against the device unless you have a big stack of hot-pink documents you were intending to scan with it.
