Maverick 88 is basically a Mossberg 500, but priced 40-50 bucks less. Mav. is always black synthetic, I believe (no wood or camo). Shoots 2.75 and 3 inch shells. Barrels and most parts are interchangeable with the 500. The Maverick Division of Mossberg is in Eagle Pass, TX. This is also where the big Mossberg warehouse is where they ship from. Mossberg has its HQ in Connecticutt.
500 is the baseline Mossy. Pump. Shoots 2.75 and 3 inch shells. Has a dizzying array of finishes (wood, various camos, synthetic black) and accessories - both Mossy and after market. Chokes are compatible with both Mav. and 535, I believe. Comes in several combo packages - do this for sure to save money. Mav. and 500 barrels ARE NOT compatible with the 535 - only choke tubes.
535 is basically a 500 but with a few changes to shoot the big 3.5 shells. Shoots 2.75, 3, and 3.5 inch shells. Comes in wood, camo, and synthetic black. However, all extra barrels I have seen are always camo - no blue (could be ugly on a wood gun with blue steel finish). I just bought my 535 (yesterday in fact) but the action seems to work differently from the 500. When I push the action button, pump, and shoot again, the action button stays depressed and you can keep shooting and pumping without depressing the action again. (This may be a flaw...need to check it out...could be safety hazard). This gun also has several combo packages.
Also check out the 835 pump model. This was the first gun to shoot 3.5 inch shells. Mossy and Federal collaborated back in 1988 to open a new magnum market in 3.5 inch shells. The 835 is a heavy duty 500 (no parts interchangeable, however) with an over-bored barrel approaching 10-gauge in diameter. This supposedly reduces recoil and improves patterns. However, makes slug shooting difficult - get a rifled barrel for 835 slugging. 835 Cost is not too much more than a 500. Also combo packages available.
The 535 is only 2-3- years old. I do not know how it holds up under the 3.5 inch shell pounding.
All above are pump guns. To get semi-automatic, get a 930 or a 935. Model 930 shoots 2.75 and 3 inch shells. If you have really big geese where you live, or just like to get your shoulder pounded all to pieces, get the 935, which shoots all 3 shell sizes. The 3.5 inch shell is a monster. Actually I have to this point only shot a 3.5 inch shell one time, in my new Benelli Super Nova. Even though the Super Nova has a "Comfortech" stock, it kicked me like a mule.