Spider-Fan Chris Carter pointed out the following dangling plot-line from ASM #238 (1st appearance of the Hobgoblin). When May and Nathan get back home May is walking through the door and a thought balloon has the following:
"That's all well and good for you to say, Nathan Lubensky! You never lost a child like I..."
Of course, the thought is interrupted by a ringing telephone and May starts talking to Anna Watson. Now as far as anyone can remember, this was never followed up on by Roger Stern or anyone else. If you know any more about this one, then mail me. Or, if you can remember any other classic unfinished stories or story hooks then send them to me and I'll do a Top Ten List of Danglers.