My preferences:
1. Winchester 1300 Defender — very simple and robust. Feeds Aguila and Centurion Mini-sheels without modification. (Mini-sheels are 1-7/8 or 2-inch shells that come in birdshot, buckshot, or slugs.)
2. Ithaca Model 37 — loads and ejects from the bottom and is perfect for left handed people.
3. Mossbeg 590 or Maverick 88 (both made by Mossberg).
4. Remington 870 — has a design flaw, its ejector. (Break one and the receiver will have to go back to Remington for replacement because it's riveted to the receiver wall.)
Another consideration are the controls for the bolt release latch (or button) and the safety position. Some guns have their bolt releases ahead of the trigger guard and some behind it. Some put the safety on the trigger guard or one, Mossberg 590, on the top rear of the receiver. Good, used pumps are preferable since they are well broken-in by previous users.
http://www.basspro.com/Mossberg-510-Mini-Super-Bantam-Shotgun/product/10218684/
This seems like a good compromise?