I just have a cheap one from Walmart. The big thing to look for, IMHO, is how big the numbers are. My next set is going to have a bigger dial so I can figure out how many pounds I've lost. Maybe it's my middle age eyes or something but dang they have gotten so hard to see.
49 years old, 5' highest weight-199lbs
. Started SBD Jan 2004, lost 47 pounds in 6 months, then slowly gained it all back.