I tell friends and relatives to let me know if they are looking for something and I'll put it on a list, because sooner or later, I will find it!
My mom needed a vacuum and I found her one. A short time later, I found a nicer one and I traded her out for the first one and sold it instead. My wife ended up with a vacuum too after I found a like new Dyson vacuum in a unit. That wasn't planned, but worked out well.....those things are awesome, and I would never have bought her one of those at retail!
My friend had an engine hoist that was about 14 years old. I got a brand new engine hoist that was heavier duty than his and he wanted it. I was over at his house, so I took a picture of his hoist while I was there. I went home and put his hoist up on CL with his phone number in the ad. He called me the next day and some guy bought it for the full asking price, so he came and picked up his NEW hoist for the money he got out of his old one. Got to upgrade to a brand new one and it didn't cost him a dime!
Another friend was looking for a welding buzz box. I ended up with a Lincoln "tombstone" welder, 225 amp. Exactly what he was looking for. He was very happy. Same friend was looking for a band saw, and I just got one of those for him too. A like new Hitachi 13" band saw.
Another friend wanted some nice top box tool boxes he could mount on his bench to store gun cleaning stuff and metal lathe accessories. I found him two really nice boxes and a bunch of tools and gave him a really good deal.
This kind of stuff happens all the time and I'm always "trading up" my tools and various stuff in my personal collection. Plus all the common household stuff others have mentioned: Toilet Paper, Windex, Cleaners, Small Kitchen Appliances, Pots and Pans, Dishes, Glasses, Calculators, Toilet Plungers, etc. Stuff you use all the time, but now you don't actually have to go out and buy it. My daughter starts college this fall, and I already have a bunch of new in the box kitchen stuff (came out of what I called the "Wedding Unit") and I will outfit her with any furniture, kitchen stuff, throw rugs, pictures and artwork, flat screen television, kitchen table, towels, etc. that she needs. She may start out with a few things that aren't quite what she wants, but eventually I'll get her upgraded to all really nice stuff. I've already helped another friend of mine with outfitting his 24 year old daughters apartment with sofa, love seat, chair and bed, along with a few other items.
The possibilities are ENDLESS!!!