I went through a Basil obsession last year, not really out of it yet
.
I ordered the seeds and grew :
Sweet Genovese,
Genovese Giant (it grows really huge leaves!),
Fino Verde (good for making pesto),
Napolitano,
Dark Opal (purple one),
Thai -Siam Queen,
East Indian Clove, (has brown stems)
Sacred,
Lemon,
Lime,
Cinnamon (strong licorice smell)
and some others I've forgotten. I've also bought some seedlings that I didn't know what they were.
Lemon is really nice flavour, but I love the Genovese ones for flavour best.
There is one called Purple Ruffles which looks like it sounds but I like the smoother leaf varieties better so I never got it. Can't seem to get hold of Greek Basil but want to.
If you want a good looking plant go for Thai - Siam Queen or Sacred Basil !