Same same. I like the sense of completion ---and, half the time I end up rereading the summaries for a bunch of manga multiple times because I forgot I wasn't interested or didn't like it.
That would be nice. There are times where I start reading something and I eventually/immediately hate it but every once and a while I will go into it anyways because I don't always remember such stuff clearly.
I wish there was a "Don't Want to Read" Button to go along with the "Finished Reading", "Am Reading" and "Want to Read" buttons.