Apparently the Zenith DTT901 has achieved some sort of cult status, since the Amazon new price is $ 159.99
and the used price is $ 64.73. Makes the two I paid $ 10 each for (after $ 40 coupon) seem a real bargain, especially since I still use them daily and they are great.
The Insignia is the same unit other than the exterior cosmetics, but was only sold at Best Buy as far as I know and is no longer listed there.
The Apex 250A is new at Amazon for $ 45.00 and new at Best Buy for $ 54.99. I still see this unit in my local Best Buy also and it seems like the price the last time I looked was lower than that; you may wish to check yourself if you have a store close by.
There are some other units available at Amazon including the Coby DTV102 which is also sold at Best Buy. Personally I wouldn't go with a Coby unless a lot of people vouched for it. The $ 40 Zinwell ZAT-970A is on Amazon.
I love the Zenith DTT901 but not enough to pay $ 159.99! Given your parameters I would say go for the Apex 250A. Good luck!