Since you want quotes, I'll just pick them from the most torrid example:

Krugman: "But in that case, why not ask CBO to score the revenue, to see if it agrees? The answer given is that CBO refused to do an analysis beyond 10 years; OK, but why not at least have the 10-year analysis?" http://krugman.blogs.nytimes.com/2010/08/06/ryan-predictions...

Krugman: "I look at how he [Ryan] has gone about selling his ideas, and I see an unscrupulous flimflammer. Think about that CBO report: getting the CBO to score only the spending cuts, not the tax proposals, then taking credit for being a big deficit reducer, is simply sleazy." http://krugman.blogs.nytimes.com/2010/08/06/how-to-spot-a-fl...

Paul Ryan's website: "In fact, Congressman Ryan’s staff did ask CBO to analyze both the tax and spending provisions in the Roadmap. However, CBO declined to do a revenue analysis of the tax plan, citing that it did not want to infringe on the traditional jurisdiction of the Joint Committee on Taxation (JCT). The JCT is responsible for providing the official revenue score of legislation before Congress. JCT, however, does not have the capability at this time to provide longer-term revenue estimates (i.e. beyond 10 years)." http://www.roadmap.republicans.budget.house.gov/News/Documen...

After Megan McArdle pointed this out (see my previous links), Krugman made this response (entitled "Doubletalk express"): "I also see that Ryan is perpetuating the runaround on revenue estimates. If you read either this article or his original response to the Tax Policy Center, you could easily get the impression that nobody would do a revenue estimate, that CBO said it was JCT’s job, and JCT balked. Even Nate Silver has fallen for this.... In other words, Ryan could have gotten JCT to do a 10-year estimate; it just wouldn’t go beyond that. And he chose not to get that 10-year estimate. So it was Ryan’s choice not to have any independent estimate of the 10-year revenue effects." http://krugman.blogs.nytimes.com/2010/08/08/doubletalk-expre...

Megan McArdle: "To be honest, I too found that passage ambiguous. Which is why I contacted Ryan's staff, who were happy to clarify that yes, they asked the JCT to do a forecast, and JCT said no." http://www.theatlantic.com/business/archive/2010/08/paul-kru...

The factually incorrect claim is that Ryan a) didn't ask the CBO to score the revenue side of his plan, b) didn't ask the JCT to give a long term score and c) didn't ask the JCT for a short term (10 year) estimate.

My second example is misdirection, not an outright lie. He opens by discussing the claim of "shifting workers out of construction", presents a graph which doesn't directly relate to the issue, and then declares victory. A careless reader will easily be led to believe he debunked the claim of a structural shift.

This is Krugman's usual mode of deception - discuss an issue, show a peripherally related graph while ignoring a much more useful one, and declare victory.

He reserves outright lies and character assassination for people he is threatened by (it's really easy to dismiss Palin or Huckabee as dumb hicks, but Ryan is smart and honest enough to admit that we need to make painful spending cuts).