Considering I watched one episode of slayers before avoiding it for a year, it could go either way. I ended up really enjoying slayers once I got past the silliness, it does grow on you.
Considering the nature of attack on titan, I wouldn't imagine any live action being very good. Death Note stands a chance, but sadly I think the formats simply are not very.. compatible. Many anime rely on facial expressions that simply doesn't work on a real person. Works as a cartoon, but when a person does it.. well they simply look silly.
GiTS however is a little more 'realistic' style animation, so far the trailer has me interested and it appears as though they are sticking fairly close to the source material.