You know what's worse than pick up lines? Nothing. That was a trick question. However, the severity of this offence is highly dependent on what is being used as a pickup line. For example, quite often men just brag about things to impress women they are interested in.
This Reddit thread is a compilation of such egotistical things that men have said trying to impress women. From the scale of basic fu*kboi to people who send butt selfies, there are all here.
You can check the whole thread here. It's an endless loop of men behaving like they have never known a single woman in their life.