xxxHOLiC Movie: Manatsu no Yoru no Yume

Both are created by CLAMP, plus there's a similar/connected scene that can be seen on both movies. However, I recommend seeing Tsubasa Chronicle movie first as xxxHolic movie carries somewhat of a spoiler for the former than the latter. 

Similar style and vibe, same wackiness 

The anime world is filled with series that boast of amazing supernatural events with unique characters. However, not many have captured the sentiment as well and as truly as Mushishi and xxxHOLIC. The lead characters do not pretend to be the best at everything they do and are fatally flawed characters whose tapestries slowly unravel to reveal its masterful weaves, which are accented by the fantastic supporting cast. There is no fan service nor the typical moe scenes. These two series are the rare art that you come across while watching as you waddle through the muck of what is called anime today. 

- They both have supernatural stuff going on, not always making sense at the first look, but with deeper meanings. - They're full of odd dialogues (good "odd" dialogues) and sometimes they give a sensation of discomfort while you don't quite understand what's truly happening.