The more recent version Windows (from 7 onwards) shouldn't need defragging anyway because the process is meant to be automatic. I'd be surprised if defragging produces any noticeable speed increase with your laptop.
However the most popular third-party application is definitely the free version of Defraggler and it won't do any harm to give it a go. (That assumes that you laptop hasn't got a solid-state drive, as you should never attempt to defrag an SSD):
http://www.piriform.com/defraggler