First things I end up buying with most of my characters;
Dull Gray Ioun Stone (with Continual Flame cast on it) - the hands-free Everburning Torch
Tanglefoot Bags - the 1st through 2nd level party's Web spell / poor man's crowd control
Alchemist's Fire - the 1st through 4th level party's Fireball
Mithral Shirt - warlock, cleric, bard, duskblade, whatever. If it's not a Druid, Sorcerer or Wizard, that's what it's wearing. I'm not taking a reduced movement rate, or blowing a feat, just to get another +1 from a breastplate!
Wand of Cure Light Wounds - oh yeah. My cleric of Wee Jas loves it, since he's too busy using all of his prepared slots to spontaneous Inflict things to death... Healing is for chumps.
Heward's Handy Haversack - like a Bag of Holding, but convenient and classy.