Tupolev 128. Flying that thing was like lifting off from earth an entire SAM site (both in size and weight!) but it was unmateched in range, autonomy and radar capabilities. Oh, and it was available in 1961.
It was no dogfighter, but since the OT specified we're considering only the early years of the cold war, the main job for an interceptor had to be chasing bombers, preferably before they dropped their nukes on friendly soil.