That is a very subjective question. If you ask which fletching style and configuration promotes accuracy to the greatest extent then I would probably say a hard helical feather fletch...5 inches preferrably. However, though that might be the most forgiving configuration/style on paper one also has to consider the increased time spent on fine tuning your rest setup because of potential fletching contact issues. Durability with feather especially in poor weather conditions also needs to be monitored.

In the "middle ground" you could pursue a slightly shorter vane or feather with less helical or even an offset fletch. The shorter vane and lower degree of twist both make for less potential fletching contact issues and thus, for the most part, an easier tuning experience. The trade-off is that they do not promote accuracy as much as the previous example but more so than just a simple straight fletch...especially with exposed blade broadheads.