Best AIO according to most reviewers and Reddit with RGB now. Do know that there are 3 versions of the Arctic Liquid Freezer II - Normal black, RGB and A-RGB. Pay attention to the size as well, the Arctic AIO radiator tend to be thicker than most.
Added the specifications below for easy measurement of your case height clearance. All dimensions inclusive of fan size
Height = 6.3cm
Width = 12cm
Length= 27.7cm
https://www.arctic.de/media/20/33/30/1621502498/Spec_Sheet_L…
If you have an AMD board (B550/etc.) be sure that the version you get is 'Revision 4' (or newer, if there is one).
The original revisions had mountings that people were struggling to fit to many AMD boards, lacking clearance.
That said, I got mine from PCCG (this post's store) back in late Aug / early Sep and it was Rev 4 stock. So I doubt they've gone backward there.