I am a Sulcata lover so I can't really offer you any insight. But if you go to the species species specific thread for each of the tortoises, you will find some folks to give you advice.
My opinion: GENERALLY, Greeks are prettier, Russians have a better personality. What matters most to you? Hermanni are pretty like a greek, but more personable like a russian... I think you will be happy with any of them. All tortoises have individual personalities and things that endear them to us.
I say Greek or Hermanns. Both are very outgoing and will come running at you for food!! The care is essentially the same. Both are great starter tortoises.