Depends on what your objective is. If you want each and every load to be accurate to a single kernel of powder then something like the [ame="http://www.youtube.com/watch?v=gfl9C0-5zYw"]Sartorius GD-503[/ame] may be the unit for you. For most the $1325.00 cost is prohibitive, though.
Another force restoration scale that is marketing for reloaders is the
A&D FX-120i. This scale can be accurate to a single kernel of powder as well but for less than half the cost of the Sartorius GD-503 at $599.95.
The next step down is strain gauge weigh cells that produce the drift everyone hates so much. Some of that can be helped with line noise filters on the power cord. The best one of those is probably the Sartorius AY-123, formerly the Acculab 123. This scale can be found for
$310.00. These are extremely accurate within 5 kernels of powder across 100 reloads. That is better than any beam scale will produce, IMO.
Then there is the previously mentioned
GemPro 250, which is a very accurate scale for the money at about $135.00. Again, your loads should not deviate more than 10 kernels of powder across 100 reloads which is pretty accurate.
Decide what you want to accomplish and which of these meets your needs for accuracy and cost. I believe each of these scales is about the best in their respective classes and price points.