Gwen + Tony
I full admit that I'm biased. My best friend became evil behind my back, and... I had to handle it. It... it wasn't my fault, but my best friend... my Peter Parker died because I couldn't see what was happening. I dont what any of that to happen to... this Peter Parker. He's the same age my Peter was when he died.
From what I've heard in the other Universes, Ned Leeds becomes Hobgoblins. Builds Bombs. Blows things up. Lots of civilian casualty. Repeatedly tries to kill Spiderman.