1. Myst (Video Game Series)
I think a LEGO model of Myst Island would be awesome.
2. Mystery Science Theater 3000
A LEGO version of the Satelite of Love would be neat.
3. Minecraft: Story Mode
Since they already have a Minecraft theme, I think Minecraft: Story Mode would be a good tie-in with the regular Minecraft LEGO sets. Maybe they could make a set of MineCon, Soren's house in the End, or the Mansion from Episode 6.
4. Garfield Comics
I'm a huge fan of comic strips, and Garfield is one of my all time favorites in that catagory. Maybe they could do Jon's house or the Farm.
That's all for now!