There should be a MR per level tier between Melee and Ranged. (1.25 and 0)

For instance, on PBE they originally had Graves with melee MR, 1.25 per level, and people thought he was OP. They removed it, and now no one plays him. That alone makes a HUGE difference in the viability of a champion.

Having a middle tier of .66 or so MR per level would allow more tuning of champs based off susceptibility to spells, e.g. Graves and Urgot could have the middle-ground MR per level.