Quoted from HookedonPinonics:

I think Oktoberfest would be a great fun theme. I can see this pin to be very beautiful (much like Houdini) with large restaurants architecture and what not. I will welcome this. It will also fit nicely and feel like home sitting in a bar somewhere.

Quoted from Genjuro:

If API ever looks at a license, i hope they would look at Pacific Rim. I love big mech battles and think this one needs to be done.
I know its not public domain yet, but it will be in just 1.5 years or so, but rosh i hope you guys start working on a machine themed to book 1984. So many good ideas in my head on how to fight big brother and a rule changes akin to the way ingsoc changed sides...

Quoted from LTG:

Amusement Park
LTG : )

Quoted from LTG:

Railroad Tycoon !
LTG : )

Quoted from bobukcat:

Everyone says the crappy South Park pin still earns well on site, we're are past due for another one that takes advantage of all the new material that's come out since then. Oh and one that's actually fun for pinheads, well designed with modern toys and display! Butters wasn't even a character on the current game, think of how much content that brings alone. I'd think it would sell well to operators as well as collectors.

Quoted from DennisDodel:

Only if it is based on the original movie. The remake is awful.

Quoted from Tuna_Delight:

A Tesla pin would look great next to Houdini!

Quoted from FlashDaddy:

America's cup would require a license I assume. They've avoided going that route so far. I'm also not sure there is much crossover between yachting fans and pinball players.
They've already done or are working on magic, historical figures, beer and cultural events. Perhaps a WW2 machine? D Day could be fun with the playfield set up like the beach at Normandy.