I have been very happy with my Sony KDL22L5000 and KDL32R400A.
KDL22L5000
Bad signal with picture freeze, SNR below 15 dB, and uncorrected errors:
Good Signal
KDL22L5000 calibration chart
My KDL32R400A has an even greater range of readings; the screen is similar. Here is its calibration chart:
So, when I bought the 32R400A, I was getting a TV and a signal level meter for the price of a TV.
KDL32R400A screen with TV connected to cable; readings are similar to OTA readings:
One of thee days I'll connect an antenna to the 32R400A and do another screen shot.
You will want to make sure the model you choose has a Diagnostics Screen. For my 32R400A:
Menu > Settings > Setup > Product Support > Signal Diagnostics
I think the smallest model now is 40". They do make a few 32", but most are Multi-System which doesn't have a tuner for ATSC.