My first street legal bike was a 1996 Kawasaki Ninja EX250. Black. I kept it for 3 years before trading it to a friend for his 1992 FZR600. I'm a firm believer that the Ninja 250 is the best beginner bike available.
I'm nice, so don't be mean to me.
If you feel like you've outgrown your 250, you've probably outgrown your helmet too.