I have two to compare, a Sunkey and an Insignia.
As some might know, I started a topic because the Sunkey just wouldn't work right. I tried it on three TVs, two older Sony's and a new LCD, and it wouldn't work correctly on the Sony's for whatever reason. Changed out the composite cable. antenna cable, and cable, and still neither TV worked. But tested on some other TVs, it worked, god knows why.
Finally gave up and bought an Insignia from Best Buy, and the difference is night and day, the GUI is MUCH better, and the unit's reception and picture/sound quality is adequate (I just wanted something to watch TV on, not an AV enthusiast by any means).
So Insignia - Best, Sunkey - Worst.