Good knives really are a treat, aren't they? Right now I live with my mother and none of our knives are particularly sharp because I swear that woman would slice her hand open with a butter knife - but the few occasions I was able to borrow my roommate's good knives back in grad school, it was amazing.

This probably depends on what kind of food you make, but one thing I will never go without again is a decent mortar and pestle. Readymade spices are all well and good, but sometimes you just have to roll your own. Plus, fresh-ground spices - especially cardamom - always smell like home to me.