I'm sure you had a lot of fun with different companions. But what about a robotic one? Yes, yes I know. There are Curie and Codsworth. However, The Automatron DLC lets you customize your robotic companion in a same manner as you can customize your Power Armor! Just read what one of the Steam users has to say about the DLC:
"This is a great DLC. It has a nice story arc and all, very nice level design, and adds more variety to enemies encountered in the wasteland. The best thing added is the robot creation. I've had lots of fun making my own robot companions to roam around my settlements and defend them. Being able to upgrade Codsworth and robot Curie adds a lot to their usability by giving them much needed buffs. I definitely think this DLC is worth the price and I highly recommend it."
Here you can buy the DLC and read many user reviews about the content.