Sometimes anime fans need to just relax and watch their favorite show. Sometimes they need to laugh. But every once-in-a-while an anime fan has so much going on that said fan needs to concentrate on something else. That's what shows like Paranoia Agent and Texnolyze are for.
If you feel the need to sit and watch an anime that forces your mind to think grab hold of one of the animes on this page and start your brain.
Paranoia Agent
Texnolyze
Serial Experiments Lain