How many of these threads have we had in the last month??
Let's try and be a bit creative here people.
It really depends on "WHAT" appears to be more dangerous to Spider-Man, and not "WHO" appears, the most hated enemy... or the most feared enemy.
I would say Venom rightfully because, being that Spider-Man at one time did wear the Venom symbiote, he knows almost every little detail about Spider-Man... his past, his secrets, how he fights, how he thinks... pretty useful info don't ya think?
I'll admit the Goblin is pretty gruesome, and can be just about as insane as Carnage, but come on, let's think rationaly here, not even the Goblin knows as much about Spider-Man as Venom does. The only thing the Goblin has on Spider-Man is that he knows Spider-Man's identity... and that he has advanced technology at his possession.