This is a difficult question, as it is wide open for debate and, of course, would vary greatly year to year.
Being a graduate of a Kansas high school I may be somewhat biased in saying that I feel that the best from Kansas can successfully compete with the best from anywhere.
But I also recognize that from top to bottom that many states have had more success at the national level. Perhaps one of the best measuring sticks to compare states with one another is the annual High School Senior National Tournament. There are weaknesses with this approach, the biggest of which is whether a state's best wrestlers actually chooses to compete in the prestigous tournament (e.g. Jeff Boyle who chose to wrestle in the Dapper Dan Classic instead).
With that said, in looking at the team score results since 1993 (when the NHSCA started keeping team scores) only four states have finished in the top 10 of the final standings in each of those ten years - Ohio, California, New York and New Jersey.
Of those four Ohio has been the most successful with 6 team titles, a runner-up finish, 2 third place finishes and a fourth place finish. California has 3 titles, 4 runner-up finishes, 2 third place finishes and a fourth place finish. New Jersey has averaged a fifth place finish and New York a sixth place finish over the 10 year period.
Oklahoma has finished in the top ten team standings 8 times, Pennsylvania 7 times, Minnesota 6 times, Michigan & Indiana 5 times each and - finally - Kansas and Iowa each have 4 top ten team finishes.
It is worth noting that Kansas' best performance would have been in 1992 - a year before team standings were kept - when they had the co-winner of the outstanding wrestler award in Justin Ware; three champions in Ware, Lyle Geyer and Justin Thaw; and nine other All-Americans. It is too bad team scores were not kept that year, as Team Kansas would have been in contention for the title.
So, based on this criteria, the rankings of the most consistently successful high school wrestling states over the past 10 years would be as follows:
1). Ohio
2). California
3). New Jersey
4). New York
5). Oklahoma
6). Pennsylvania
7). Minnesota
8). Michigan
Indiana
10). Kansas
Iowa