Can't go wrong with a cute little 4-stroke 250cc; pick one that suits your needs. The CB250 is very versatile, the XT250 is lightweight and well-suited to trails, relaxed sports bikes like the ZZR250 are nice for touring... Only thing I'd advise against is really ... "aggressive" sport bikes, unless you're racing you might as well get one that's more comfortable because the performance won't differ much.