Fluids for an ML430

Sorry if this is a trite inquiry, but I'm going to try to do normal maintaince on my ML430. MB says that you need to use all their brands of fluids; in my experience, manufacturers always do. Can I use off-the-shelf antifreeze, brake, power steering, and transmission fluids or is there a good reason to pay Mercedes prices for these items? Also, any brand recommendations would be greatly appreciated.

Thanks much.