For fabulous leaf color you just can't beat this one. It has sort of garish blazing orange flowers, but I just remove them and enjoy the leaves.
It was originally sold as 'Durban' but now is known as 'Tropicanna'. I got them at Lowe's both last year and this.
I've seen pictures of gorgeous green/white variegated foliage on 'Stuttgart' but I have bought tubers twice, from two different vendors online. Both times they have grown plain green foliage with delicate apricot flowers. I wrote back to both vendors and got the same answer - the variegation is what they call a 'chimera' and it disappears randomly. They also can't stand the direct sun here if the foliage does come up variegated. The white areas burn.