Does anyone know what weapons go with which characters as far as best proficiency goes?

Here is a write up from IGN. I didn't look too deep, but they have class trees in the write up. 

I'm assuming gunzerker doesn't care what he uses. Assassin would be snipe. Soldier would be machine guns. Siren would be SMGs. That is an assumption based on the first game, but I read somewhere that althoug assassin will snipe, he has more effective tools for up close combat with the sword and the cloak.

http://www.ign.com/wikis/borderlands-2/Classes?objectid=94188

The gunzerker has skill tree bonuses for shotguns, I believe. They're all optional, though. There's no default advantage for an assasin using a sniper, for example. Just a skill tree bonus that makes it more powerful in his hands vs. another character.

With BadAss ranks, any character can be very proficient with any gun over time. Each character has 'options' to specialize in certain weapons if you so choose. Example, Zero has ability to enhance zoom and stability while under fire - that no other character has access too as a skill (if he wishes to put points in it...) obvious sniper bump.

My impression is that gun choice and character class are not tied together as tightly as they were in borderlands 1.  So it doesn't matter as much.  You still should carry one of each to diversify your ammo needs.  I'm always running dry.

There are badass challenges for getting so many kills with specific gun types, I think. Unlike this first game, though, completeing them does not make you better with specific types of guns, just gives you more badass rank, which you can spend on things like overall accuracy. That's what the proficiency did in the first game, and then made it so that by the time you finally got around to using smg's, you weren't proficient in them enough for them to be useful.

Liking the badass ranks... pushed over 600 last night. My stat buffs are in the 3-4% bonus now across several attributes with two characters at level 10, one at level 14 and another at level 7. I prefer this system over the previous proficiency system by far. 

Ya a profile level attribute system that enhances all tasks is really a next level idea for these types of arpgs.  I hope it gets copied in other games.

I've seen the 'zerker have a few class mods that give bonuses to shotguns so I guess that might be his weapon of choice. Aside from that, it really doesn't matter. My Zero is running around with a shotgun right now and the critical hits from that are killing even badasses in one shot, meanwhile my commando sits back and snipes with his roof mounted turret.