I have been playing the heck of out Borderlands 2 (with the gore turned off and language filter on). I love it! I probably love it too much.
However, if they make a Borderlands 3 (After the prequel), I have some serious suggestions:
1. Include the skins with the game and make them a free DLC. Instead of charging for skins, charge for different models - you know - things that take REAL effort to create! Different clothing models and different vehicle chassis designs, not just a different paint job.
2. Instead of discovering WHOLE guns that range from very common to legendary, place common to legendary PARTS of weapons so we can design our own weaponry. You could even task the Mechromancer (hint hint) to put them together with greater success than others. Maybe each class are better at making different types of weapons with greater success than other classes. The Psycho could have a better chance of making a cool grenade with greater radius and/or damage. Th Commando could be better suited in designing or modifying Assault Rifles - and maybe even have it so a gimped secondary weapon could be attached underneath the rifle barrel to fire in unison.
3. Make the world SEAMLESS like Azeroth. Only in specific instances have a portal to that region. It really takes me out of the game when I have to wait 8 seconds for the next "area" to load. Learn from Blizzard...
Anyways, that's all I have!