The Sony a6000 is an awesome camera -- it was awarded Gold by DPReview and recently came out on top of the mid-range mirrorless camera roundup. On top of that, the a6000 is available at a $100 discount for Black Friday. The Sony a5100 is likewise a great camera, and is one of DPReview's best cameras for beginners, with the same great sensor and quick autofocus ability as the a6000.
However, when choosing your first interchangeable lens camera, I find it helpful to consider not just the camera specifications but the system as a whole -- especially the lenses and to some extent its accessories (e.g. flash). So if you're considering the a6000 or a5100, you may want to check out its lens selection to see if it has the lenses that you'll need. The italicized ones are the lenses I have.
Note: to the extent DXO has tested the lenses below with the a6000, you can expect identical results for the a5100 due to the identical sensor.
UPDATE: Sony has new FE lenses that can also be used with the a6000, a5100 or other E-mount APS-C body. I added those to this list.
