How to say "Please, go in front of me" when standing in a queue?
In this situation, I would say "您先请", which works fine.

"您先请" means 'after you', which is very polite.

If you really want to say 'Please, go in front of me' in Chinese, you could say "请走在我前面吧". However, this sounds a little bit strange. Note that you stand in a queue, you don't go in a queue. So "请站在我前面吧" is better.