What is the best wireframing tool for websites?

I have used pencil for a while and it works great for me, here is the list of top 10 opensource wire framing tools http://speckyboy.com/2010/01/11/10-completely-free-wireframe-and-mockup-applications/

Visio, Axure RP, Photoshop, i use both Axure and Photoshop

Visio and Axure from a visual functional side Borland Define it for storyboarding and Photoshop suite for the branding and animation

1- Photoshop
2- Illustrator
3- Visio
4- Fireworks
5- Indesign
6- Balsamiq Mockups and if you need more you can visit this page: http://www.creativebloq.com/wireframes/top-wireframing-tools-11121302 There is 20 best wireframing tool for web design.
Good luck