Ignoring obvious planned expenses, such as meals, my last 3 purchases:
(1) Yamaha 2330 Shepherd's Crook Cornet - I've been waiting a few years to find a good deal one one of these, and I snagged it in fantastic shape for $150 shipped off of eBay. Very much researched and thought-out, not impulse.
(2) IBM Thinkpad A21m Laptop - This was pretty impulsive. I caught wind that the local campus salvage store was selling off some old stock of Laptops, and for $130, I figured.... what the heck, it'll give me something to do in classes. Works great, runs Linux perfectly, and I'm rather pleased, although this WAS impulsive.
(3)
Music CD - Definatley not impulsive. I spent about a month researching and tracking down this disc. It's the best-mastered, best sounding recording of some of the definitive performances of some of the best songs of all time. Best CD I've ever purchased or heard.
No, I'm not very impulsive at all. I think before I buy. Well, except for occasions like dates. I can be impulsive there.
Jam it back in, in the dark.