From the top of my head, the best ones IMHO are Blender and Zbrush. I am trying to learn them both.
Zbrush is commercial, and was in the start mostly sculpting software, the modelling was added later.
It is easy to learn - You can start with sculpting almost intuitive. But it is very powerful once you go deep under the hood.
Blender is open source - it was from the start modeling-sculpting-animation tool. It has so many features.
It is great piece of software but it is much harder to learn - at least that was my impression.
Sculpting tool is also very powerful - but somewhat more complicated interface than Zbrush.
Of course, once You learn it, it can do magic
I also use FreeCad sometimes (also open source). FreeCad is very useful in modeling when you model from technical drawing -
it is possible to enter exact dimensions using "constraints" and get 3D presentation of the object.
Hope that this helped