A used Ninja 250 is the overwhelming recommendation new street riders will get in the US.
Mostly because we don't get the 125's or other small street bikes over here. Would really like to see some of those.
If you take care of it, you can recoup almost all of what you paid for it after a couple years riding.
Many hang on to it because they're so much fun.
Photos of other stuff:
83 CB650 Nighthawk I bought new.
I sold it in '05 shortly after getting a used '98 BMW K1200RS
Then I picked up an '03 SV650 as well because I missed having a smaller bike.