Soundwave on 28 December 2015
You know the other thing I'd look at? Movie franchises. I'd try to lock down a few of them, even cheap ones for 10-20 years.
Bond would be my ideal one, but if you can't get that I'd look at IP like
Mission: Impossible
Rocky (could use these characters in a Punch-Out! game too)
Scarface
Fast & The Furious
Jurassic Park/World
Tolkien/LOTR
I'm not sure which of these would be available, but I'd reckon you could grab one or two for cheap.
