What's your favorite site for comparing laptops specs?

http://www.NotebookCheck.net has thorough reviews. In addition to the standard productivity and game benchmarks they also objectively test parameters others don't like screen brightness, color space, refresh rate, fan noise, audio performance, webcam resolution, etc. Their test suite is consistent over time and they test a lot of laptops so you can use their database to check two models head to head.

I usually just use a spreadsheet when I'm down to a few options. That way, I can compare stuff like IO, battery life from independent testers, etc., things that just aren't present in comparison websites.

Apple.com for my work laptops

Acer.com for my friends' Chromebooks

Any website with used laptops.