There's a few for me: Yuuko Ichihara from xxxHOLiC [pictured] Mion Sonozaki from Higurashi: When They Cry Ryner 琵琶 from The Legend of Legendary Heroes Rui Ninomiya from Gatchaman Crowds, to some extent (*cough*I wish I was that smart *cough*) Light Yagami from Death Note, to some extent (*cough* God-complex *cough*) Milly Ashford from Code Geass
Honestly, I dont have a single character that reminds me of me as a whole, but I have a long 列表 of characters that remind me of certain aspects that make up are/were large factors of me.
There are A LOT of characters each with their own traits and Mashiro Shiina is one of the most similar to me, not just because of her personality, but also we both 爱情 art :3