Obviously there has been attempts to make rating systems for sites in the past. Almost all have had dismal at best results.

What or how would you rate sites?

My idea is to rate sites on 3 levels:

Content: Adult - General - Children

Traffic/Use: High - Average - Low

Ad Friendly: Takes over your computer - Banners and Buttons - Ad Free

So a site with a AHT rating is adult content with high traffic that takes over your computer with all the ads and misdirects. A GAB is what would be considered a normal everyday general content website and a CLA is a low traffic, child safe and ad free site.