Once you see it:

seriously, i don't care what the creator of the file format says, the public has spoken on this one: it's pronounced GIFF, with a hard G. even his explanation of it backs this up: "Graphics Interchange Format," has a hard G sound. it's not pronounced "jraphics."

GIF with a hard 'G'. Regardless of what the creator thinks, the G in Graphics is hard so it's only appropriate to say GIF with a hard G. I don't know anyone who says "JIF" (probably because they know I would disown them).