These are what I'm usually ISO when keeping items.
Note: when I say Dual/Tri Res, it meansFR/CR/LR. NO PR
The more stats, the better.

Weap:
~melee~ battlehammer / martel / executioner / naga / ancient axe / lance
- most would keep 160ed+ even w bad stats
~caster~ shard or any wand/staff
- 20fcr & Tri res 25+ / energy&mana are bonus
- wand +2 & 20fcr & 3 bonespear & resist 20+ / +1Teeth or BoneWall, energy, mana, MORE resist are bonuses
- staff +2 & 20fcr & 3 blizz & resist 20+ / +1IceBlast or IceBolt, energy, mana, MORE resist are bonuses
- staff +2 & 20fcr & 3 fireball & resist 20+ / +1FireBoltBolt, energy, mana, MORE resist are bonuses

Shield: Grim / Bone / Spike / Barbed / Pavise
~din shield~ +2 & priz / fhr and str are bonus
~overall~ shield must have 30/20 block to be usable & priz / ed, strength, fhr are bonus

Hat&Armor: Any, depends on what you like(looks). majority prefer bone&grim looks for hat, armor is your choice
- fhr / 25life+ & dual res 20+ on each / high ed & strength(armor only) is always bonus

Belt: any within str req (usually 4 slot, 3 slot as temps, 2 slot not very popular)
- fhr & strength & 25 life+ & dual res 20+ on each / high ed & rep life are bonus

Gloves: caster usually uses magefist / if not then any gloves within your str req
- 5strength+ & dual res 20+ on each / ed, dex, mana&life leach are bonues

boots: any within str req
- 20fwr+ & dual res 20+ / fhr, dex, & mana are bonus

ammy:
- +2 & priz / fcr, str, dex, life, mana, energy & rep life are bonus

rings:
~caster~ 10fcr & dual res 15+ on each / str, dex, life, mana & rep life are bonus
~melee~ 8 str+ & 8dex+ & 80AR+ / min&max, add damage, life, rep life & resistance are bonus

Uniques to keep that'll most likely be helpful for you or others:
Shard
Gull
MageFist
Bsnap
Tarn
Silk
Gskin
HotSpurs
Ward(45+res)

Edit:/ RavenClaw for uniques as well if chanter available for you