depends what's your purpose of your phone

both can do what you specify. Example

Priority 1 - Camera
Priority 2 - Social Networking
Priority 3 - battery life

example

G version got some probs and very little custom ROMS for modders.

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Added on April 18, 2012, 11:21 pm
Seems that the lumia 800 suits u better.

for me lumia 800 have better camera without 3rd party app
http://www.flickr.com/photos/thenokiagalle...9608885/detail/

If you talking about apps - SGS II wins
If you talking about responsiveness - Lumia 800 wins
Internet browsing = Both okay but SGS II have a plus due to the flash support
Ease interface = Lumia 800 wins

Lumia 900 have a bigger screen of 4.3 inch and a bigger battery capacity the rest its the same with the Nokia 800. we do not know when is the official launch of the Nokia Lumia 900. If you dont mind a smaller screen, smaller battery capacity and wants to get a free Nokia purity headset worth RM499 then just go for Nokia Lumia 800

you missed so many chance there done so many roadshow buy a Nokia Lumia 800 non white get a free Nokia purity by monster worth RM499.

You should drop by the nearest Nokia Store to check whether is the promotion on

This

thats a risk u need to take maybe got promotion maybe not.