which one is better??

[rlord]

GIGABYTE 8600GT 256MB GDDR3, Silent-Pipe II, HDTV, 2xDVI, PCI-E

or

Sapphire HD 3650 512MB GDDR2 DX10.1 HDTV DVI PCI-E‎

 

[mactronix]

To do what with ?

Mactronix

 

[rlord]

for games like crysis, Mercenaries 2

 

[falcodakrzz]

If you want to play Crysis then aim for at least an 8800gt...Both those cards are low end...Out of the two id say ATi 3650,

 

[dirtmountain]

Both would be underpowered for Crysis, you'd be playing a low-medium settings and it would also depend on your monitor resolution. Here's a handy graphic card hierarchy chart that shows relative power of different GPUs.
http://www.tomshardware.com/reviews/Best-Graphics-Card,2011-6.html
Both those cards are on the same tier, so no real difference. Let us know your budget, where you're shopping at (newegg if USA usually) system specs and resolution and someone will come up with some ideas.

 

[dokk2]

8800gt all the way,8600 is like yesterday's 7600,not bad but has limitations..

 

[dirtmountain]

This card on sale at Newegg would perform about the same as the 2 you had listed (same tier), but is only $20 after rebate.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121082
but if you want good gaming performance with modern games, you'll have to upgrade.