Most underused/underrated actors?

I was just rewatching lost today (whats new), SOS to be precise, and was thinking to myself Wow, Rose is a really good actress. They should've used her more., same with Bernard. I mean, even though they were around since the first 2 seasons, we didnt see a whole lot of them. I know SOS isnt a very popular episode, but towards the end when she tells Bernard her cancer is gone, and he says he'll stay on the island if she wants to I just smiled to myself, especially because Rose's story is based off of L. Scott Caldwell's real life (In case you didnt know, she married a man with cancer for less than a year, he died while filming season 1 I think). So I was wondering who you guys thought were some of the most talented, but least used characters/actors on Lost. And please, dont say any main characters (Michael Emerson, Terry O'Quinn, etc.) They're outstanding but we saw plenty of them! I say (besides Rose and Bernard) that Danielle, Alex, Helen Norwood, Annie, Isabel (The blonde other who reads jacks tattoo, not Isabellaaaa!), nikki and Paulo (Lmao ya right, kidding) Naomi, and of course CARMEN REYES! Come on! Why is there a dead Pakistani on my couch?