The brand names stand behind their products. This is especially important when you need a replacement part—and you WILL need a replacement part, sooner or later. (Sooner if you are new to airbrushing.) With Harbor Freight, etc., you may be on your own—or up an air line without a regulator (as in down the tube, fast.)
That being said, remember Martinek's Law of Tool Selection: "The only tool you can afford is the best tool you can find." This particularly applies to brand name products. All of the major air brush makers make good air brushes, but some also make "entry level" (read, "cheap and not very good" products. Get a higher end Badger, a Thayer & Chandler (owned and sold by Badger), a Paasche, or even an Iwata, etc., and you'll probably be happy. Get a low end Badger, and you might not. Get an Aztec and one of two things will happen: you will swear by it, or you will swear at it.
As for a specific recommendation, I love my Thayer & Chandler Omni 4000. I can do almost anything I need or want to do without changing tips and needles. I also own a very old, very serviceable Paasche H that I now only use for metallic paints, but it served very well for many years in all applications.