Style of tableofcontents

The short answer for almost all TOC, LOF, LOT, etc. customisations is first to see if you can achieve what you want using the tocloft package. Nine times out of ten, you'll be able to.

To complement @Geoffrey's answer, note also that if you use the memoir class, the tocloft is included (reproduced ?) and you can use the same functionalities. The memoir manual has a complete chapter about the customization of the ToC, LoF, LoT.