Originally Posted by white cab
Originally Posted by gurnE
You mentioned speed so I assume you're looking for a sports bike?
As I've said above, any modern Jap 600 will do. You can't buy a bad one really.
GSXR600, R6, CBR600RR and the new ZX6RR are pretty full on and aggressive.
The older ZX6R and the CBR600F are pretty good all rounders but still bloody fast
Go sit on a few and see which you like the feel/look off

my yz 250 2 stroke is fast and 0 to 60 would do it in around 6 to 7 secs the same as a standard crf 450 four stroke (off road if you can get the traction) i think if you can ride fast off road it will make you a better rider when it comes to going on the tarmac.
these days you have to worry about the other people on the road and not yourself and have to be exteamly vigilant the most experianced riders will tell you this also.
and i still belive the r6 is the bike for me.
Mate your 250 will do 60 in ALOT less that 6 or 7 seconds, depending on how old it is try 3 or 4.... And it will get to 60 quicker than a 450 as well
When I had mine, I rode it next to a mate on his roadbike at 30 and was amazed at how slow 30 was on the yz. Actually worried me quite a bit because I used to ride between riding spots with no helmet on etc alot faster than that...