sequential circuit chaser light
This is called a Larson Scanner and there are many ways to do. 

Personally, I think easiest way is to use a cheap (less than $3) micro-controller like a PIC or AVR and a bit of software. Search for "minimal larson scanner" on google for some designs. 

You could overkill and use an Ardunio-based board. This makes your work a little easier, but costs a little more. Here is a project I did a few years ago that can do Larson Scanner and several other programmable patterns...

http://josh.com/ALSO/

If you really want to solve the problem with discrete logic, here is an example design, but you can see it is more complex and lots more parts than the micro-controller solutions...

http://hackaday.com/2011/04/20/larson-scanner-using-7400-series-logic-hardware/