Been through the game a dozen or so times using various characters.  Most fun so far has been a good little sun-bro helping other people fight bosses etc...  In my 500hrs so far I have only invaded once as a dark spirit and a dozen or so times as a forest helper.  
I have noticed during my last run-through I was starting to get bored of the game and decided I really needed to shake things up.  So, on my latest character I have decided to become a rather low-level Gravelord.  Spent the last couple of days at SL 28 in the undead parish gravelording and I have once again found some excitement in the game.
Interesting tid-bits:  A lot of Dark Spirit invaders will simple wave, bow and exit out of my game once they see I am actively Gravelording.  A few will fight though.  Almost all Dark Spirits will attack any Spirit of Vengeance invaders in my game.  I will always let them dual it out mono-o-mono.   
My plan is stay in the Undead Parish or perhaps the depths Gravelording for a while.  So I wish you all a happy Gravelord infection 
 
I am trying to work my way up to becoming a Dark Wraith.  For some reason I have always felt guilty about invading other peoples games.  I have no problem with people invading mine, but their is a tinge of guilt about going in and fucking someone else over.  I hope to get over that......