These are my personal favorites (Zoson), in order of most wanted to least wanted.
Luck Dodge BD
Wide Bore Luck Interrupt Increased Butt Damage (IBD) Increased Crit Chance (ICC)
Hunters are much, much more useful once they have wide bore. Add high luck and you get lots of crits. Combine with ICD and the hunter charge move for really BIG hits. Interrupt works nicely here since you can stop entire lines of zombies and from long range. ICD doesn't make much sense due to the fact that hunters hit pretty hard already, and you'll usually be hitting multiple targets. More crits vs bigger crits will almost always be more advantageous.
Luck Dodge IWD DDS
Increased Spread legs Luck ICC Interrupt IBD
Assaults are the early-challenge monsters, and late challenge cleanup crew. Increased spread will allow you to steamroll through the early challenges, and increased luck and crit chance to make them more capable of getting one hit kills. Interrupt is difficult to use on assaults, and my experience with it has been inconsistent. It seems like even with a 100% interrupt weapon, sometimes an assault won't interrupt everything in the cone of fire. ICD doesn't make sense due to the fact that you simply want more crits with an assault in general to bring their damage up to the kill range. Two assaults combined are really powerful, get two large overlapping cones!
Luck Dodge Retaliate IWD DR
Arc Luck ICC Interrupt butt-knocking IBD
Warriors are the guardians of your squad. Getting surrounded? No problem! Stack dodge with luck, and if you have retaliate you get free hits. Large arc to hit as large of an area as possible, high luck and ICC for more big hits. Interrupt is also difficult to use on a warrior, as usually you'll just interrupt one thing anyway. You can take it, but generally I prefer it on my ranged attackers. ICD makes no sense due to the fact that warriors already hit decently hard - just go for MORE crits.
Luck Dodge IWD DR
Luck Interrupt IBD Butt Range ICC
Shooters make one or two targets(with charge) dead, or stop one target from doing anything. High luck for more crits is always good since shooters do high damage, this allows you to definitely make tanks drop. However, ICD is also really awesome here due to charge ability synergy. Interrupt is GREAT on shooters due to their high damage. A half damage interrupt shot from a shooter is awesome for handling tanks and armored zombies if your melee is busy.
Luck Dodge IWD Retaliate DR
Swift Strike Luck Interrupt ICC IBD
Go kill that one thing, scout. If you're lucky, kill two things or overwatch. Even though ICD synergizes with scout's brain stab, it's not very useful in general to take ICD. Scouts hit so hard already that you just want more crits and more swift strikes. Stack luck, icc, and interrupt. Like shooters, since scouts hit so hard, an interrupting scout is very strong.
Luck Dodge Retaliate IWD Decreased intellect
Concussion Luck Interrupt sex acts ICC IBD
Bruisers suck. Any time you stun something with a bruiser, you could have killed it with basically any of the other classes. More crits from luck and ICC is desirable since crits bring bruiser damage up into the range of being effective for killing. ICD synergizes with stun, but well, why would you bother finishing off a stunned target with a bruiser rather than another survivor?
Armor Dodge DR Health Wrestler
Dodge is the most important armor trait. Again, DR, and HP do not matter at all if you don't get hit. So, why DR over more HP? Because DR is HP agnostic and removes the damage directly from the attack. The bigger the attack, the bigger the raw reduction(20% of 100 = 20 vs 20% of 150 = 30). Additional HP does not scale in this fashion. Naturally, wrestler sucks - avoid getting into a struggle in the first place.