The Athletic has a list of the best NCAA and European free agents: https://theathletic.com/4213022/2023/02/21/college-chl-european-hockey-free-agents/
I know most of the college names (few of Euro ones). My list adds a few named I believed should be added.
There are probably a couple of tiers. I think the most sought after would be something like (* would be August window, everyone else once their seasons are over)
McDonough*
Livingstone
Johnson*
LaCombe* (but he probably signs with ANA)
Perets (he didn't list)
Chrona*
Nelson
McAllister
Skoog
Guys Pronman ranked, but I don't know well are
Austen Swankler, C, Bowling Green-CCHA
Luke Krys, RHD, Brown-ECAC
Travis Mitchell, LHD, Cornell-ECAC
Cooper Black, G, Dartmouth-ECAC
Guys Pronman ranked, but I don't think are NHL prospects
Akito Hirose, RHD, Minnesota State-CCHA
Ryan Siedem, RHD, Harvard-ECAC
Max Sasson, C, Western Michigan-NCHC
Others he mentions that could elect NCAA free agency this summer
Dominic Basse, G, St. Cloud State-NCHC (CHI)
John Farinacci, C, Harvard-ECAC (ARI)
Mitchell Gibson, G, Harvard-ECAC (WAS)
Carter Gylander, G, Colgate-ECAC (DET)
Nikita Nesterenko, C, Boston College-Hockey East (MIN)
Matt Steinburg, C, Cornell-ECAC (COL)
I don't know the European names all that well other than Okulov and Pulli (And didn't know Brannstrom had a brother). Rest were new to me.