Neither. The correct phrase is "long time no see".

As retSam said "Long time no see". Leave the "you" off the end, it is implied. Virtually identical to the Chinese "好久不见". This is a recognised expression, used often. In normal English you'd write something more like; "I have not seen you for a long time" or similar. or It's been a long time since I've seen you.

I would say "long time no see!" - meaning that you haven't seen each other for a long time.