We are perhaps a little too close in time to the Secret Gospel of Mark to be fully objective about its placement at no. 2, but Ossian certainly belongs near the top. Thomas Jefferson raved about it, as did Goethe. James MacPherson actually managed to make one of the first waves of Romanticism in an era that Classicism dominated. He had not been able to get his own poetry taken seriously until he came up with the idea of “editing” the oral works of Ossian. I get the sense, however, that MacPherson more or less stumbled into his fakery.
I get that sense, too. In a sense, we can regard MacPherson as trying to do at a very early stage what later folklorists would also do (but less clumsily), namely, shape the native poetry into a national epic; the most important modern case was that of Elias Lönnrot, who constructed the Kalevala out of fragmentary Finnish traditions. The difference is that what Lönnrot was doing was fairly clear and above-board; his source material was made available, for instance. MacPherson's texts do have a root in Highland folk poetry; MacPherson's problem, I think, was largely that he went too far in claiming real authenticity for his work, and then just let himself get carried along by the tide. I have a few links on Ossian at Houyhnhnm Land.
UPDATE: In the comments, Sharon reminds us of Iolo Morganwg, MacPherson's Welsh counterpart, and points out a website on MacPherson and Morganwg. Meanwhile, at "The Little Professor," Miriam adds a Victorian candidate, the Awful Disclosures of Maria Monk.
UPDATE2: Follow the Hypotyposeis link above for further discussions of the issue.