 If you liked xxxHOLiC |  ...then you might like Natsume Yuujinchou Shi |
I'd recommend the whole xxxHolic series. It's also about a boy who can see the supernatural and spirits bother him. Natsume Yujinchou is more focused on interaction with youkai though, while xxxHolic focuses on supernatural cause and effect. xxxHolic also has more action and is a bit darker.