Which one is correct?
1)I'm looking forward to see you.
2)I'm looking forward to seeing you
Thanks in advance 
and... sorry what does it mean?
Hi,
The second answer is correct because "seeing" is a gerund acting as the object of the preposition "to". Gerunds act as nouns, but the word "see" can only be a verb. "To see" is the infinitive, and in that case the word "to" is not acting as a preposition. The phrase you are asking about needs a prepositional phrase--an infinitive is inappropriate.
Another common way of saying it is, "I look forward seeing you". I can't say for sure it's grammatically correct, but it sounds natural. Probably, sticking the preposition "to" in front of "seeing" is more grammatically correct.
Charley
The 2nd:
I'm looking forward to __ing
I'm looking forward to watching a movie
I'm looking forward to hearing you sing
I'm looking forward to cooking with you.
I'm looking forward to eating.
second one
You want to say the second one.... to me.
Second one.. since you need to keep the form of the verb same in the sentence.
I think that's the grammatical reason.
If it was I look forward, then it could be see you though that might sound little bit strange.
If it was I am looking forward, then it would be seeing you
-grammatically correct
-sounds right
I vote for the second one
I think Brits would always say "seeing".
The problem here is the "see" vs "seeing". Most people would say either one of those sentences with the same intended meaning without even thinking about it.
In the second one, there seems to be some arrangement or agreement for both persons to see or meet each other, while in the first one there is no such arrangement. That's just what I think.
I don't think I can say for sure that any of them is grammatically incorrect.
If it were me, I would use "I look forward to meeting you" when have not met a person before, but have been possibly corresponding by telephone or email and it is a reasonably formal relationship.
I would use "I look forward to seeing you" when I have already met a person and am anticipating seeing him or her again.
More casually:
I'm looking forward to it. or Looking forward to it.
I don't want to start a war here, but you can say either :
I look forward to seeing you (usually when it is someone you have not met before)
or
I'm looking forward to seeing you (in anticipation of meeting someone again)
but either will be acceptable in either situation.
Please ignore Armand's answers. They are both incorrect!