I've always loved moto-x bikes: very short gearing and lots of poke!
I've had several racingbikes and on all of them I've fitted a smaller front sprocket 'coz I want instant response!
Rode my mate's GSXR600 the other day and it did my head in! I'm too far over the bars because of my height and you have to cane the tits of it to get anywhere fast and then it still doesn't really give you THAT feeling of acceleration if you know what I mean...?