I'm not a retro / classic fan but of the 4 you've picked out deff "America"... But then they are all Triumphs so I'm sure you will enjoy whichever one you decide on.... 
125gJoe said:Tough call...
I didn't like the Thruxton though - something's way "off" on that one!
It's the seat and back fender. They look like they belong on a different bike.
I would go with the Bonneville T100.