No, I dont mean by anime adaptation of a manga but you know..Remake of any anime that felt bland, for some reason needed to be remade, or put simply, remade was made for fun in some Studio Cases. There are things like that out there, you know? Anyways..
Kanon 2006 (remake of Kanon's anime many years ago)
Tetsujin28 2004 (A nostalgic but new modern remake of the classic mecha anime Tetsujin28)
Negima?! (remake to Xebex's poorly done anime productuion of Magister Negi Magi back in 2005 and let me tell you, I love this a lot!)
Pwerpuff Girls Z (remake of Powerpuff girls. Yes, I know they loli-fied all of our fave ass whooping girls but at least its funny )