Suggestions for a good digital converter box for maximum 4:3 format screen fill

[Electronic M]

I use the Zenith DTT-900, DTT-901, the LG, and Insignia rebadged of those boxes. They've got enough reception strength that 30-40 miles west of Milwaukee I can get most channels with just 6" of wire jammed in the antenna hole...They work well with a vintage antenna and a balun for it (excellent if it's a vintage UHF bowtie antenna). They have a Zoom button that lets you choose between letterbox, Cropped (the sides of 16x9 lopped off and the rest used to completely fill the 4x3 NTSC output), and Squeezed (16x9 image squished horizontally so it fills the 4x3 NTSC output without anything being invisible)....They have RF output too.
They're old 2009 models and there's a cap which fails in some (dieseljeep posted which one on this forum), but they still work great.