I am in the process of finishing my basement with steel studs and am almost ready to work on the electric. What kind of boxes do you use when working with steel studs?

There are various type mounting brackets on varios boxes, see images...

outlet box with steel stud bracket - Google Search

Generally speaking, any flat mounting bracket that you can drill sheetmetal screws through into studs will work.

They offer various clips that will clip onto the face of the stud and will hold any box.

Ok... so I can use a plastic box with the metal clip to screw into the face to the steel stud?

I wasn't sure if you had to use metal boxes with steel studs.

No, as long as you can find a box that you can support with a steel stud clip, or one with a side bracket you can mount with screws, you will be fine.

Romex cable and plastic boxes are allowed to be used with steel studs.

The important thing to remember is to use a grommet in any hole that a Romex cable will pass through a stud.