Apparently when Kenneth Branagh tried to do this 13 years ago with his Mary Shelley's Frankenstein, there was an unshot version of the script by Frank Darabont. Del Toro claims that draft was, according to Adams, "pretty much perfect." I admit I never bothered with Branagh's film. I'd rather watch "Johnny 5" play the monster than Robert DeNiro (or at least watch the robot read the book, as he does in Short Circuit 2). So, I can't directly say what didn't work about the adaptation. All I know is that it seems to have been pretty much disregarded by everyone. That said, I'm also not the biggest Del Toro enthusiast in the world. I'm not going to exclaim that he needs to make this and that he would deliver the best Frankenstein ever. I would, however, love to see him make the attempt.
Del Toro discussed a few other, less-wishful projects with Adams. The filmmaker said he's no longer attached to the following projects: Born, which was to star Jennifer Connelly; Creature from the Black Lagoon; The Wind and the Willows. He said he may still one day get to shoot his scripts Mephisto's Bridge and The Count of Monte Cristo. He will be producing Neil Gaiman's adaptation of his own comic, Death: The High Cost of Living, which Del Toro has someone in mind to star in (and it isn't Selma Blair, despite her interest). He is also already at work on the non-greenlighted adaptation of At the Mountains of Madness, which he said is a tough one because it's "expensive, R-rated and doesn't have a happy ending" -- something along the lines of large-scale horror flicks like Alien, The Exorcist and The Shining. Meanwhile, Doug Jones was asked about the Silver Surfer spin-off, but the actor hadn't been approached about anything of the sort. Yet.