Which, gtx260m or 5470

Neither, thier notebook graphics . The 260 is more powerful but only supports DX10, but has more muscle. By the way what notebook are you getting?

I would definitely recommend the 260m over a 5470. the 260 has far more brute power then the 5470. very easily 3 or 4 times the power, since's you'll be on a notebook, eyeinfinity is out of the question. and to be honest if your not getting at least a 5770 mobility, the card probably won't be able to handle dx11 very well. So hands down gtx 260m over 5470 if your just comparing the gpus, but it would help to know the rest of the potential systems

Its an ASUS G51VX RX-05 ( GTX 260M) and Asus K52Jr-X2 (5470)

Well the the laptop equiped with the 5470 has one of the new i3 330m, which is going to be bit more powerful, then the 5470. But still the primary bottleneck on most games is gpu power, so i would still believe that the Asus with a 260m would be more powerful in games. But in more desktop oriented stuff the one equiped with a 5470 will have more power, and better battery life, as the i3 is based on 32 nm construction, and the 5470 on 40nm, whereas the core 2 duo is on the 45nm and the gtx 260m is based on the 55nm