>>18505667
Depends on what you need it for, and how comfy you are with wrenching. Large aircooled single cylinders (enfield, nowadays, or old enduros) are easiest to work with and look nice, mid-size supersports or sporttourers are best for daily driving bcs. the fairing keeps rain and mud away, and if you can't wrench for shit, there's some (BMW and Motoguzzi) that don't have a chain you need to adjust.
Or you can do as I did and get a large, aircooled racer, then mod it for max power and enjoy having to wrench all the time, getting wet every time it rains, and always having the neighbors after you for the startup noise. But hey, at least you'll be a real man (TM).
If I had to get another bike, I'd go for a honda CB750, because that bike automatically adjusts valves through oilpressure. put a belt drive on there and mod the seat and bar, and you've got a caferacer that won't require maintance more than twice a year.