[Tuor in Gondolin]

I tend to think a two-part Hobbit would work well both
artistically and financially. One of the problems PJ had
with the lotr films was arguing for longer ones, a 2 part
Hobbit could be in the two hour + range each, making
movie theaters very happy by, of course, ensuring more
playing times per screen. And if you put in the White Council
meeting and attacking Dol Guldur there's plenty of material
for two films. Among other seperate scenes you'd have An
Unexpected Party, the trolls, Rivendell, The Goblin King Incident,
wolves glade, eagles aerie, Beorn, the Enchanted Stream, trudge
through the forest plus Bilbo tree climbing, elves partay,
giant spider fight, etc. etc.

A good cutoff point could be Thorin and Co. entering Mirkwood
while the White Council invests Dol Guldur and that conflict begins.

P.S. I do like The Might's ideas above. the one really good of PJ's lotrs (FoTR)
was helped immeasurably by that prequel, and, since Gollum only has
one scene in the book you could bookend appearances at the beginning of Part I
and ending of Part II (with Gollum emerging and vowing to find The Precious
and get Thief Baggins.

P.P.S. A scene with Smaug attacking The Lonely Mountain while someone
recites the early version of the poem would be really cool (although a hot time
for the dwarves).

P.P.P.S. While it rather stretches time and geography (like that would stop PJ) you might even
have Gollum peeking out of the Misty Mountains and watching one of Smaug's strafing runs.