I haven't been using my NEX-3 as much as my other cameras over the last few months because I wasn't overly happy with the native E-mount lenses I owned and I felt almost depressed over the fact that I "needed" to use my legacy lenses on my NEX-3 to get ideal image sharpness most of the time. That changed today with the arrival of my Sigma 30mm f/2.8 lens from B&H. I won't say this is the best lens I own but I absolutely will say it's the best native E-mount lens I own. I took this snapshot of my daughter using the 30mm wide open at f/2.8 and I'm VERY pleased with these results ... particularly for a lens that only costs $200:
NEX-3
E 30mm F2.8
30mm
f/2.8
1/50s
ISO 640