There is no way to name the "top five" airbrushes.
That's like asking us to list the "top five" colors or the "top five" models. No way it can be done, everyone has their own personal preferences.
Just about any name-brand airbrush will do the job. The biggest real difference is between single action and double action, and gravity feed vs. suction feed... and again, there is no "right" answer, it's a matter of personal preference.
A double action brush gives you more control over the spray than a single action, because you can alter the amount of paint that you're spraying by how far back you pull the trigger. But a single action brush can also do a great job. Same with suction feed vs. gravity feed... they both have their pros and cons and personal preference is ultimately what it comes down to.