According to concept art, the RZ-1 A-wing interceptor is the fastest ship in the rebel fleet. It is certainly one of the sleekest fighters in the Star Wars universe. This model by Thomas Jenkins is high on my list of fan creations. The off-set tiles down the front of the ship lend a realistic look, without detracting from the clean lines. I also really like the angled detail on either side of the front fuselage that smoothes out an otherwise sharp edge.
The slight angle of the engine pods is quite accurate to its on-screen inspiration, and there are some excellent details along the back of the fighter as well, including an asymmetrical ingot on one side, and a very nice rear thruster detail using 2 spoilers in white.