Quite frankly, implementing WYSIWYG editors (and choosing the right one) for Drupal websites has been a pain in the ass the past few years.  For a while I bounced between FCK and TinyMCE - both integrated in the right fields fine and played well with IMCE for image uploads, but I remember finding their markup dirty (lotsa br tags etc..) and clients getting quite confused with line breaks in the editor not being truly mirrored on live content.  Of course, some of this is due to configuring Input Formats properly, but then there's also general interface and aesthetic issues with those mentioned editors.

Recently I've begun implementing HTMLbox on a bunch of sites - its simple, seems to markup html pretty well, and affords site users the basic buttons for simple formatting and link embeds [look out for a more in-depth review soon].  However, one downfall with it is a reliance on IMCE for facilitating embedded image uploads.  For anyone who's ever used IMCE, you'll know how confusing it can be for anyone unfamiliar with inline editing - though it integrates with the editor, its interface is still seperate and requires a lot of styling effort to pretty it up etc...  read more »