Love the Gargantuas idea. And I agree, as over-used as Mothra is, she's always a welcome sight. But I think she's pretty tough, and I hate how they've been killing her off in nearly every movie lately.

Gargantuas aside, I'd choose Rodan. I really like that big reptile and feel that he could inspire an interesting story. I think I'd pit him against another monster, perhaps Megaguiras, since Rodan liked to eat the younglings in the original, it might be fun to see him against an adult one.

P.S. After giving this more thought, what I ACTUALLY like to see is more mecha-monsters. I think Mothra vs. a Mechamothra would be a blast, as would a Gargantua vs. Mechagargantua or Rodan vs. Mecharodan. Or, if we could have another monsterfest, a group of our faves vs. their mecha counterparts in a big battle.

DOCTOR 13