Beretta PX4 Storm. Can be a 9mm, .40 cal or even a .45 ACP. Its DA/SA with a manual safety and has a picatinny rail to mount a flash night if you'd like. Little higher than your budget, typically $550.
I own the Compact, which I CCW and use as a home defense gun and I love it. Never thought id care for a polymer gun but this piece has really impressed me. Not to mention the trigger is so buttery smooth and with the rotating barrel there is less recoil than most other firearms in the same caliber. Cant even compare to a Glock.