Thanks for the replies guys.
I didn't know it was related to the PS1 variable, but once I learned that, it was easy to add this line to my .profile
Code:
export PS1="\u@\h:\w\$ "
It does what I need, but with a nasty exception: if I su from a user terminal, it won't load root's .profile for some reason and as such the prompt is just #. If I source .profile the prompt changes to the proper one. What to do?