LastSpartan,
Smooth-cast 300 has been talked about the most on this website. I don't know what brand name is "The Best" per say.
Tensile strength is what you want to look at.
I think there are TONS of brand names and I don't know them all.
The resin I use is from a company that was kinda talked down here.
I love the stuff and use their silicone as well.