There’s been many incarnations of Charles Xavier over the decades, there’s the comics, TV Shows and movies (both McAvoy and Stewart) so while the basics of his character has always been the same, there are differences in the different media.
I first encountered Charles Xavier in the 90’s X-Men cartoon and then in the X-Men: Evolution cartoon and I thought he was great in both shows. He’s wise and wants to look out for his students but he still makes mistakes. Xavier likes to give off this aura that he knows everything – he is a telepath so that does help – but because he think he knows a lot of stuff he’s sometimes blind to what is actually going on which can have interesting and sometimes bad consequences.
Charles Xavier in the original X-Men movie trilogy is one of the best things I’ve ever seen. Patrick Stewart is one of the most perfect casting choices in any superhero franchise. You can feel the responsibility he has for his many students, especially as they aren’t just teenagers, there’s many young children under his care as well, and he also cares about his X-Men. Charles struggles to look after mutants and protect humans as well, he wants to do the right thing but that often means there’s difficult decisions to make.
Charles Xavier is pretty much the ultimate old, wise, powerful character that wants to do good but whose plans don’t always work out.