膜拜 (mo bai)
It means admiration and worship. It refers to the act of putting one's hands together in a flat manner and placing your hands above your head -- a form of prayer and worship.
However, on the internet, it can sometimes also be used in a manner that is ironic. For instance, this can be when someone did something incredibly naive or dumb, another person can say "哇，我膜拜你了” (wa, wo mo bai ni le) which means like "wow, I admire you" but of course this is meant in an ironic way.