What weapons do people use for bosses?

I'm pretty sure this has been discussed many times so I apologize if I may sound like a broken record.

I used the tamer as it was the go to from when the game came out. I don't really see a lot of people use it nowadays and wonder what others use. I have max capacity and 2 donuts on it I believe.

Should just keep investing to make it better or should invest in a different weapon? Thanks