Editors' note: This story was originally published in January 2012. The latest update adds the Fujifilm X-M1.
The category of interchangeable-lens cameras subsumes a variety of capabilities and designs. You have the familiar dSLRs, large-bodied models that use a reflex mirror to enable the use of a through-the-lens optical viewfinder. Then there are Sony's SLT (Single-Lens Translucent) models, which incorporate the same phase-detection autofocus system as dSLRs, but with a fixed mirror that requires the use of an electronic viewfinder (EVF) rather than an optical one. And then there are the mirrorless models, which generally use contrast-detection autofocus and, if they have a viewfinder, it's an EVF. Though they're sometimes referred to as "compact system cameras," they're not all compact; in fact, only a handful could really be classified as such.
The mirrorless models cover a lot of ground. For instance, there are compact models designed for people dissatisfied with the image quality and performance of point-and-shoot models and who are looking for more. Then there are the models for advanced shooters who want the speed and photo quality of a dSLR without the bulk. And there are a host of models that slide along the continuum between the two.
This isn't to say that the rest of the ILC crowd doesn't measure up; though some have weak aspects, such as slow performance or overly large bodies, there don't seem to be any real losers among the entire field. You can find good options on our list of best interchangeable-lens cameras. There are a truckload of mainstream models I haven't yet reviewed, including the Olympus PEN E-PL5 and PEN E-PM2; Pentax's tiny Q7; the Nikon 1 J3 and V2; the Panasonic Lumix DMC-G6 and GF6; Sony's NEX-3N; and the Samsung NX300, NX20, and NX2000 -- and of course the yet-to-ship Galaxy NX. Whew! Plus the field is heating up for the more expensive models, such as Fujifilm's X-Pro1 and X-E1, Sony's (hopefully soon-to-be-replaced) Alpha NEX-7, and the Olympus OM-D E-M5 and E-P5.
So with that distinction in mind, here are some of my favorite sub-$1,000 -- with lens -- mirrorless models.
Sony Alpha NEX-6
Now priced comfortably less than $1,000 at about $800, the NEX-6 is my pick for the best overall model and Editors' Choice in this class, and better than a lot of competing dSLRs. It's fast, full-featured, and well designed, though it's since ceded the best-photo-quality crown in this class to the Fujifilm X-M1. Read the full review of the Sony Alpha NEX-6.
It's not the fastest and falls short on video quality, but the X-M1 delivers the best photo image quality for less than $1,000. It's also one of the more attractive cameras in this class, and doesn't skimp on features, with a tilting LCD and Wi-Fi (although Fujifilm's connectivity implementation was rather weak at test time). Its big brother the X-E1 offers a more retro/analog shooting experience -- and the same strengths and weaknesses -- with a lot more photographer-targeted controls and an electronic viewfinder, but because it also ships with a better lens its kit price is over $1,000. Read the full review of the Fujifilm X-M1.
If you want the least expensive model that will still give you the performance and photo-quality boost of a worthwhile upgrade from a point-and-shoot, the E-PL3 is a great choice. It's not really the best in any one particular aspect, but it delivers a combination of photo quality, performance, features, and design that should please a lot of shooters looking for something better than their current snapshot camera or camera phone, and though it's relatively old that means the price is a lot easier to swallow than that of some of the newer, more advanced cameras. The same goes for the last-generation Sony Alpha NEX-F3, which comes in an extremely close second; equipped with a zoom lens, it's bigger than the E-PL3, and the selection of E-mount-compatible lenses is smaller than that for Micro Four Thirds. Read the full review of the Olympus E-PL3.
Sony Alpha NEX-5R
For the model most suited for shooting video at a reasonable price, the NEX-5R gets my vote. It's a slightly better camera than my last pick for this use, the NEX-5N, though it's got similar video quality, so if you're price-sensitive I think you'll be equally happy with the cheaper model. For either, I suggest you consider the 16-50mm f3.5-5.6 Retractable Zoom lens if you'll be shooting with something other than a prime. Read the full review of the Sony Alpha NEX-5R.
Looking for specs and pricing? Compare these mirrorless cameras head-to-head.