Slint's "post rock" now? Odd... I can see them inspiring bands within the genre, but I typically think of stuff like Godspeed or Do Make Say Think when I think of post rock. Post and math rock have really been meshed together, I guess.
So, in that case: A Minor Forest.. but I'd say that's math rock... Gastr Del Sol.. but to me that's folk.. so I'll say World's end Girlfriend.
http://en.wikipedia.org/wiki/List_of_post-rock_bands