Amami Island
This is the largest of all Neos. The growths may get to 12" plus inches across, and the flowers are twice the size of standard Neos, with up to 10 flowers per inflorescence. Fragrance is quite stronger as well.
Gojyo Fukurin
Of the Neos with striped leaves, this is a good one. The colors are green and white, and very clearly defined. It's a vigorous grower, flowers large, with a sweet fragrance.
Hisui
Called Jade, this variety has green flowers with a white lip. Plants are compact, and bloom when young.
Shutenno
Red Emporer is the most popular of the red/pink flowered Neofinetias. Plants are vigorous, getting up to 8" across, and flower profusely. Great fragrance.
Tamakongo
One of many Bean-Leaf types - these are nice and compact plants, with a star-shaped flower.
Your culture will affect the growth rate and size of plants, as well as depth of color of both flowers and leaves, and fragrance.
Post some pics of your Neos!