Recent 51st overall picks:
2021: Ville Koivunen (Carolina)
2020: Theodore Neiderbach (Detroit)
2019: Simon Lundmark (Winnipeg)
2018: Akil Thomas (Los Angeles)
2017: Zachary Lauzon (Pittsburgh)
2016: Kale Clague (Los Angeles)
2015: Brendan Guhle (Buffalo)
2014: Jack Daugherty (Nashville)
2013: Carl Dahlstrom (Chicago)
2012: Dalton Thrower (Montreal)
Lots of good players taken in that 40-60 range throughout the years though. Tristan Jarry, Tyler Bertuzzi, Artturi Lehkonen, Mackenzie Blackwood, Erik Cernak, Roope Hintz, Vince Dunn, Alex DeBrincat (39th), Samuel Girard, Carter Hart, Sean Durzi.
Some recent Kings second round picks: Francesco Pinelli, Samuel Helenius, Helge Grans, Brock Faber, Arthur Kaliyev, Samuel Fagemo, Akil Thomas, Jaret Anderson-Dolan, Kale Clague, Erik Cernak, Roland McKeown, Alex Lintuniemi, Valentin Zykov