First of all, never trust anyone's opinion as to what is bad. If it works for you, it doesn't matter.
That said, there are properties that have more use than others.
1. LRC: If playing a necromancer, mage or mystic (and to a lesser extent, a Chiv user), LRC is desirable.
2. LMC: Everything uses mana, from skill masteries to spells to weapon special moves. The higher the LMC the better (capped at 40%, but some non-meditation armor gives not-displayed bonuses above the cap and displayed value)
3. Mana Regen: goes well with LMC.
4. Additional stats (especially Mana/INT, but also Stam/Dex for warrior types)
Everything else is pretty much template-driven (you want SDI on a mystic or Mage, SSI on Warriors, etc.)
Avoid Antique items as a rule, but they can be useful for short term use until you find something equal or better without antique.
Brittle items can't have max durability added/restored (but start at max). Very useful, unless something that takes massive durability hits (weapons & shields on characters with weapon skills and/or parry).
Prized items are expensive to insure and cannot be blessed, but otherwise are good choices.
Cursed items cannot be insured or blessed. More prone to being looted.