I kind of painted myself the narrow window of your qualifying "what I've seen so far" and excluding Ring of Honor talent from the list. I've also abstained from KENTA simply because we don't know what he's going to be like in New Japan yet. I've also kept out the New Japan dad set that may have been great in their prime, but I wasn't there to see that greatness at it's fullest potential. Anyway, what's left is a modern roster of mostly non-gaijin talent.
1. Kota Ibushi. He's a true rounder in every respect of the word. I've touted him as an uncrowned best in the world before and I stand by it.
2. Hiroshi Tanahashi: The guy is a legend who raised up the company in it's darkest time. I think his time in the spotlight is winding down though. The days of Tanahashi pulling a great match out of anyone aren't far in the past, but they're growing in the rear view in my opinion.
3. Kazuchika Okada: While I don't think he's the lauded best in the world, few have the fundamentals and flash that Okada has. Okada only has big matches. Even in G1 settings an in-form Okada tends to deliver.
4. Tomohiro Ishii: There aren't many relics from Inoki-ism that I enjoy, but Big Tom Ishii is one talented and diverse athlete. He never gets higher than the NEVER Openweight title though. I'd love to see his hard work pay off.
5. Tetsuya Naito: I only put him so low because he tends to live the gimmick hard when he's not in a position that he doesn't want to be in. A motivated Naito is worth more than the names listed above him on this list, but like his character he does have quite the rebellious streak of apathy. He's got a unique style to him that makes the prima donna breakdowns worth the wait though.
6. Zack Sabre Jr.: Kind of like Naito, a motivated ZSJ is a very fun thing to watch. Luckily he seems quite motivated in New Japan.
7. Evil: Evil's blue chip material. He's been great when put against the aces of the company, and he's even given Jericho one of his better in-ring efforts in New Japan. I think he's more motivated than Naito these days because he still believes he could earn that top spot. I do think there are things about Evil that need fine tuning before he rises up the ranks, like the character and the finisher, but the charisma, technique, and dedication are all there.
8. Sanada: Sanada's right up there with his tag partner when it comes to motivation and genuine drive. He was trained by Great Muta and you can see it in his sleek in-ring style. He can fly, he can grapple, he can be deadpan and hilarious, or he can be a young and hungry up-and-comer giving Okada an unexpected run for his money. Part of me thinks I should switch him and Evil out, but I think Evil's had way more to overcome than Sanada when it comes to creative direction and looks in general.
9. Will Ospreay: My personal bias against Will puts him low on this list, but like with Omega, I can't deny that the kid's talented. I've actually quite enjoyed Will's transition into the heavyweight style. He does fewer unnecessary high spots, he doesn't scream like a pig with his throat slit as much while selling, and he's genuinely leaned into the fundamentals. I think New Japan sees him as the future boot filler of Kenny Omega, and considering Will's following I think it's possible. I'm still not a huge fan, but he's bringing me around lately, and like I've said about Omega in the past: you can't deny talent even if you don't particularly like it's practitioner.
10. Hiromu Takahashi: I struggled between Takahashi and Ishimori for the ten spot. The absence of the Ticking Time Bomb has made the heart grow fonder though. Like Naito, the guy wrestles like no one else in the world. I do wonder what he'll be like when he returns. Part of me hopes he's more grounded and less risk taking, but another somber part of me knows that crazy streak is what makes Takahashi special.