Radio France International ranks Obama as the "most popular" leader, and FP offers a justly acerb acerb critique of the methodology. Right enough, but it's also a useful reminder of how American leaders are often more (John F. Kennedy) or less (George W. Bush) popular away from home. Cf. the lunatic enthusiasm for Chairman Mao among pampered UMC westerners in the 60s. On the same theme, I guess I'm a bit surprised that Hu Jintao came across with a bad rep, considering that I suspect that the ordinary westerner-on-the-street probably has no idea who he is.
And speaking of not knowing who he is, here's a guy that probably belongs in my rotisserie league competition of for "best" (huh?) world leader--Kevin Rudd of Australia, until lately no more than a name to me, apparently held in high regard by Barack Obama, Bill Clinton, perhaps even Hu Jintao to whom, by reports, Rudd can talk back in Mandarin.
Oh, and I Meant to Add: If you're looking for a world leader who is truly popular in his own country, I suspect the champ might be Vladimi Putin.