I started off on dirt bikes... a Honda CR250 and CR500, then when I was at school a Suzuki TS50X... Since then I went full road bike and lever looked back... too many bikes!
So in order...
TS50X - My first bike awwww, sold it to buy a stereo.
ZZR250 - First bike after passing my test, crashed into an oncoming car
ZZR1100 - probably too big of a step up given that it made 220bhp at the rear tyre
CB125 - Sudden purchase after writing off the ZZR1100
Bandit 600 - Boring but easy to crash
Diversion 600 - first go at panniers, sold it to go on holiday to Egypt
ZZR600 - Got this after Egypt, gave it to Eloise when I got the Blackbird below
CBR1100XX - Massive touring fun, crashed in epic style by surfing it down the A1 in London
CBR1000rr - Sold before I got the chance to do something silly
SV650 - Got this to try and keep my license clean(ish)
Hayabusa - bored of clean license, this a full power version with a little extra... GPS said I did 212mph on the M4 (clocks said 225)
Aaaanyway, out of the two I could go for the smaller bike, the big one is a lot heavier and won't be as much fun, or as good on a bit of dirt, if you won't go near dirt ever, I would buy a ZZR600 for about the best all round bike I have ever owned.