Spider-Man & Venom: When Spider-Man discovered his new costume was in fact an alien symbiote attempting to permanently bond to him, he enlisted the aid of the Fantastic Four to remove it. Rejected, the symbiote bonded with Eddie Brock whose hatred for Peter Parker helped form the deadly adversary Venom!
Wolverine & Deadpool: While Wolverine and Deadpool may not have battled as often as some, they have a bond that ties them together whether they like it or not. Both were parts of the Weapon X program and it was an injection of Wolverine's healing factor that cured Deadpool's cancer - forever linking the two.
