lulz should have known>>10263597
Depends. I'd say anime first because you'll want to read the manga badly afterwards. But don't if you can't stand reading stuff you've seen already.
There are significant differences. It does seem like whichever you do first determines whether you like the anime or not.
The anime is fuckwin in my book, but I saw it first. Glad I did. Annoyed I had to read so much of what I knew already, but fucking worth it to read.
Either way, prepare to either be traumatized or turned on.