Galaxy s battery is good we cant say it is bad either it is just good
but in video playback test of gsmarena
Iphone 4
Samsung wave
Samsung galaxy s comes third
i9003 lacks super amoled screen but the super lcd is also gud and in i9003 you will get 1650 battery which is 150mah bore than samsung galaxy s i9000 but it doesn make much difference
if you are talking about battery then dont go for htc desire hd its battery back up problem is widely discussed on the internet just google it
N8 is very good cellphone really i like it but if you are ok with symbian OS then you should get it 
otherwise on a cheaper side you can see Samsung omnia hd

