i am by no means an expert but since i spent the time cross checking where seeds made the list i figured i would share. i first took the top 45 from '09 and '10 in tennessee and listed seed that appeared in top 45 for both years, there are 20. i then found each rank for those 20 seeds from '07-'10. and did the same for the arkansas and mississippi test sites. so over 4 years in three locations the most a seed can make the list is 12 times.

the top ones are: (includes tenn. miss. and ark. sites)
bullseye - 10 ranks from 1 - 42
braveheart - 8 ranks from 1-43
trio - 7 ranks from 1 - 34
cezanne R2 - 7 ranks from 2 - 36
GE - 1 - 7 ranks from 10 - 40
Rk5 - 7 ranks from 5 - 46
faith - 6 ranks from 3 - 44
hemi - 6 ranks from 13 - 42
monet - 6 ranks from 4 - 31
shanandoah elite - 6 ranks from 15-41
van gough - 6 ranks from 7 - 37
firecracker ls - 6 ranks from 7 - 42