Whats the best Cpu i can use?

Here is a link showing the compatible processors for your motherboard -

www.cpu-upgrade.com/mb-Gigabyte/GA-MA785GT-UD3H(rev._1.0).html

As it shows, all processors available currently(from the AMD camp) are compatible with your motherboard.. Just make sure you have the latest BIOS version before making the upgrade.. As for whether the about to be launched Bulldozer units will be compatible or not, we have to wait and see.. The maximum probability is that it won't be compatible..

From that list looks like the X4 965 is the best bet if he wants to stay with his current mobo. I wouldn't recommend the X4 970, waste of 10$ more, the 965 can be Oc'ed easily with a good cooler.

Hmm insightful indeed  

Heres what i got and vs upgrade , Is it worth it for the money?

http://www.tomshardware.co.uk/charts/desktop-cpu-charts...

Huh, since u already have the X4 620, i'd recommend that you first try to OC that CPU, cause going from the X4 620 to the X4 965 won't be much of an upgrade. Or sell your current platform and get an Sandy Bridge i5 2400/Gigabyte GA-P67A-UD3-B3/2x4GB DDR3 1600MHz platform.  

Which video card do you possess currently..?? Please give your full system details if possible..