I just went through this a year ago on my first pump gun. Best thing to do is identify areas that are important to you (cost, longevity, versatility, aesthetics, feel, construction, way it shoulders, etc). Within the $300 price point, most commonly bought guns are (and I am sure I'm forgetting some:
Remington Express (several variations)
Benelli Nova (same) my gun
Mossberg
Stoeger P-350

Wingmaster is great but it run's $550-600 new.

What it came down to for me was feel and the nova pump felt the best and would take all sizes of shells, all of them are statistically reliable. Hope this helps.