Right, my sister has come back from Aussie and wants her crappy 19" tv/monitor back

So I am moving my Samsung 223BW onto the file server and looking for a new monitor for my gaming machine, ideally at least "one-up" from the 223BW.
I was thinking of going into the 24" market since the prices seem reasonable, 1920x1200 is tasty and will give my 4870 a work out, but monitors is not my strong point.
Budget is ~£250 but will pay more if it is really worth it (not going to pay £800 for example on one that is ace for photoshopping, wasted on me

but £350 on a fantastic monitor for gaming I will give some thought to).
I honestly have no idea what to go for and what to avoid, so if anyone has any advise, much appreciated!
Anyway, time to give her this crappy "technika" and worry about what I am going to do
Cheers all!
Gav