Who is Best at Display Ads Based on Browsing History

I know there are companies out there that will display ads based on your browsing history. It works like this, say you are looking at a new car, a Ford, and Ford is part of some display ad network. Then days later you go visit a bank website to research Auto Loan rates and there you see a ad for Ford, sometimes even the specific model you were looking at.

I believe Yahoo (now MSN) offered this functionality based on search history.

I forget the term used, thought it was something like Re-Targeting or Re-Marketing (I think the latter has more to do with previous buying patterns.) I believe it stems from the fact a lot of people make purchase decisions days or weeks after they do their research. So display ads about the stuff they were looking at in the following days increases your chance of converting those decision makers (encouraging and impulse buy.) That's just one way to look at it.

So who are the top companies offering this type of advertising service? I swear one of them the name in on the tip of my tongue. They're huge and been around a while (not Google.) I think these are also referred to as "2.0" or "Next Gen" networks. I think DoubleClick was the name I was trying to remember (now owned by Google)