Definitely our best all around forward, he's just an absolute beast. I think Quinn Hughes may have something to say about him being the best American though... it's a tossup probably.
But I've been saying for years that a healthy Jack Eichel is the best American center in the world. He tends to get underrated by stat watchers because he doesn't cheat for offense and he plays in a fairly conservative Vegas system, so he doesn't pile up points in the regular season.
He's also had injury issues that he often played through, further hurting his counting stats. A healthy Eichel in a run and gun system would be a consistent 110+ point player
But it's not his regular season scoring that sets him apart - it's his play in the playoffs. He's just one of those rare players who's skillset shines through as the games get tighter. He might have the most powerful stride in the league, he's just so effortless when transporting the puck through the neutral zone, and is Jagr like in the way he protects the down low. And he's become a rock defensively, with one of the longest sticks among centers in the league.
He was an absolute 2 way monster for us in the four nations, and was far and away Vegas's most dominant player during their cup run. Not to take anything away from Marchessault, but Eichel was robbed of a Conn Smythe. Marchy was clutch AF, but he was a passenger on that line - so many of his goals were just him receiving Eichel passes for wide open shots. Eichel assisted on 9 of his 13 goals, 6 of which were primary. And 5 of those primary assists were absolute dimes.
His 2023 playoff highlight reel is just nutty.