The Mainline (I'll get to the "favorites"... allow me my digression)
Pete Boettke is a proponent of distinguishing between "mainline" vs. "mainstream" economics. Mainline economics is economics built on the solid foundation of scientific practice and the insights derived from economic science - unalloyed by ideology, fad, etc. Mainstream economics is a principally sociological designation - it is whatever is fashionable at a particular point in time, and it may or may not coincide with the "mainline".
I think Pete's parsing of what counts as "mainline" is pretty hard to defend - but I like the concepts themselves.
It seems to me the two indisputable anchors of the mainline of economics are Adam Smith and John Maynard Keynes. Smith's analysis of the market order and the gains from exchange speaks for itself, I think. For most people Keynes speaks for himself too - but since he doesn't speak for himself for a lot of my somewhat idiosyncratic group of readers I'll clarify. After Smith a lot of people took the conclusions about the order of the market and made some inappropriate extrapolations about both the stability of the market and more importantly the optimality of that market order. There was also some more specific vague thinking about savings and investment, as well as the role of expectations in the market order (the market is, after all, a place where people's planning for the future is an important motivation). Keynes cleared up a lot of this, bringing in a lot of very solid, old concepts from people like Malthus and the mercantilists (whose respective metaphorical babies had been thrown out with the bathwater), as well as new ideas, and integrating a lot of the advances of early twentieth century thinkers like Wicksell, Marshall, Hawtrey, Fisher, Kahn, etc. And, of course, aside from being an excellent synthesizer, he made his own contributions (particularly around clearing up the confusion surrounding savings, investment, and interest). It was good economics and it set the course for much of twentieth century economic science.
So - who is the modern anchor of "mainline economics"? Without diminishing the many great economists out there today, it seems to me one obvious answer is Paul Krugman. Krugman's ties to Smith are obvious. Krugman essentially won the Nobel Prize for bringing Smithian economics back to trade theory after a long, long, long Ricardian hiatus. Oh, and he applied similar ideas to lots of other modern problems too. His ties to Keynes are obvious as well. I think Krugman's channelling of Keynes really came on the scene with Japan in the late 1990s. Of course many people at Princeton at the time participated in this revival of thinking about Keynesian themes of expectations, fiscal policy, and liquidity traps (Bernanke, Woodford, Svensson, etc.), but Krugman clearly became this group's public and intellectual face.
So there is our mainline: Adam Smith, John Maynard Keynes, and Paul Krugman. It's not a faddish looking list. You may disagree with some of them, but these are guys that had good, clear answers to the premier scientific questions of their time, and most importantly - time has demonstrated that the answers hold up.
Krugman is a hot potato because he's our contemporary and he has political views that he expresses. Fine. Maybe you don't like everything that Smith and Keynes each thought (and I know I have readers that question both), that's fine too. But if you think that either of them is somehow a subverter of economic science or that they haven't made monumentally important scientific contributions, I think you need to reevaluate your objectivity on these questions.
And they are the clear favorites
I think economic crises offer an opportunity for serious critical reflection. In a sense, they raise the stakes of the science, which gets people to pay a lot closer attention. So given this focused stance, who are economists' favorite economists? According to a new paper by Klein, Davis, Figgens, and Hendengren (2012), Smith, Keynes, and Krugman dominate the list. There are four categories: pre-20th century, deceased 20th century, over 60, and under 60. Adam Smith wins the first category, Keynes the second, and Krugman the fourth. Granted, the academic societies surveyed have specific leanings, but even among the AEA and the regional associations, these three dominate. This is very good to see. Friedman and Mankiw also do well, which I am also happy to see.
The over 60 category is interesting just because it's so diverse. The overall winner is Gary Becker, but there was a lot of diversity across associations. Arrow and Stiglitz both did well too.