Is it better to apply for GC in the US?

Hey can anybody tell me if I should go to the US to apply for GC? I know I can apply for GC from my country but I heard that being in the US gives you better chance to get approved?

to Pauline:

I don’t think so…. Applying for GC in the US is not a plus to your case approval. Your credentials should matter the most.

to Pauline:

I agree! You don't have to come to the U.S for your GC application.

Thank you all for answering my question! How about the processing time? Will I get my GC faster if I am in the US?

to Pauline:

Processing time for I-140 should be the same. But if you are doing it from outside US, you will need to go thru consular processing to receive immigrant visa at the US consulate. You can't file I-485.
You can probably call your consulate to check their processing time for immigrant visas.