Blogging Software

I am growing very VERY VERY tired of wordpress comment spam! Becuase it's so standardized and widespread it's an open target to these attacks. Here's an analogy.. using wordpress instead of a homebaked or less popular blogging system is like using a PC instead of a mac when it comes to viruses! Geez. Oh well this is not meant to be a rant, rather I want suggestions. What do you guys suggest I switch to?

Presently, I'm considering Mephisto. I don't like wordpress becuase I think it's too feature rich andheavy weight. I want something lightweight that's easy for me to hack into and add my own code on. I truly dislike the notion of upgrading. Once I setup a blog the code is hacked apart by myself so much that upgrading just isn't an option. So what are your thoughts? What do you recommend? Should I just build my own blogging software? Should I try out Mephisto? Are there any other decent CMS systems that are preferabbly Rails based?