Best caching for high traffic website

[eluser]boltsabre[/eluser]
If you want to look at your page load speeds, try www.gtmetrix.com, it's very good for a starting point, gives you a break down from both googles and yahoos page speed testers and hints, tips, information about various options to you.

Oh, if you a really high traffic site with an international audience, also look into setting up a CDN, they have help greatly by hosting your asset files across the globe!