BMW R80, 90, or 100
They have possibly the best stock seats ever made, easy to maintain, plenty of power, luggage options galore, and if you join the BMWMOA, you get the Annonymous Book which provides help in literally EVERY locale in the country (and most of the world)
Any Honda ST
Kawasaki W650
Triumph Bonneville
Concours (?)
thought about Moto Guzzi? G5 or T3 maybe?