Wysiwyg is default editor that comes in wordpress. Besides,wysiwyg there are other choices which might be best alternative for you. But , I am happy with this default editor. But I came across the strange problem with wysiwyg editor. While trying to post new article , I was unable to see this editor . I tried clearing cache and also from different browser also but didn’t work for me . After few hours I see my apache log for error. The problem was the permission in wp-includes folder. Yesterday I changed the permission in that folders ,thus it stopped working. Finally wysiwyg start working with folder permission of wp-includes with 755.
The solution might be changed according to the type of problem .Please check your apache log for errors.