this is a age thing and about as accurate as talking about a length of string we have had many great players, however people will always put current players near the top of any list, they forget how good the former players were!
Best for me (and it can only be personal opinions:
these two are head and shoulders above the rest,
then perm anyone from
Gerrard, Callaghan, Keegan, Souness, Elisha Scott, Phil Neal, Tommy Smith, Hansen, Lawler, Billy Whizz.
All either game changers or just the embodiment of what this club stands for in football.