There are ALOT of good deals for GPS during Black Friday. Depends on budget and features you want. For large screens I think the best deals are:
Best Buy Garmin - nüvi 1300LMT GPS 4.3" w/ Lifetime Traffic & Maps $129
or the TomTom - XXL 550TM GPS 5" also w/ LIfetime Traffic & Maps $129
At Taget, the Garmin nüvi 1450 LMT 5" w/ Lifetime Traffic & Maps $159
Note if you can do without the Lifetime Traffic & Maps, Sears and Radio Shack have deals on some of the same models, or similar Magellan 5" for $30-50 less. A few have just traffic, just maps, or neither.