As others have mentioned, a 250 is a great place to start but you may be tired of it before you're done paying for it. What is it that is most important to you in the bike purchase. Are you looking for something that will inspire a lot of confidence and ensure that your early riding experiences are good ones? If so then the Ninja 250/500 or Suzuki GS500 may be the ticket in the sporty category (don't forget that there are relatively low displacement metric cruisers that also fill this bill nicely). If you are looking for something that will keep you entertained for a long time even after you've gained some experience, consider an SV650 or Ninja 650R. The SV in particular has a strong following and upgrades for handling are well documented. If you are looking for something that will get you mad respekt at the lot y0, then you need a stretched out, custom painted, nitro-turbo 'Busa, with lots of chrome spikes on it.