OK, how about some rational ideas on gadgets: but before I do, lets define "live without." We're not talking "I'd simply die" without, or that i would kill myself if I didn't have, we're clearly talking "my life would not be the same" and thus that other life is not this one, and this one would be gone.
1) Fridge/freezer and a stove/microwave. Real hard to eat without it! That, or a car to go get food elsewhere, but I have a hard enough time affoding groceries for the family, let alone eating out every last meal... Without having electronics at home to store and cook food, I'd have no other cash with which to live my current life. Going with this theory, the "gadget" in question is actually a TIMER...
2) Coffee pot. Personally, it's bad enough I need coffee, but mine goes further and makes it on schedule (gringing and all). All I need to do is remember to empty it, which is easily done as it sits next to the kitchen sink above the dishwaster... If it wasn't automated, I'd fall asleep on the couch waiting for it to brew, and then I'd be unemployed and have a real hard time having much of my current lifestyle...
3) Home netowork switch/wireless base station. Broadband is a given (a service, not a gadget, so it really doesn't count in this list), but without a network switch/firewall or an AP, it's pretty much useless to me. I can live without TV, even without a PC, but without a basic network not much in my house works (blueray, smartphone, VoIP, printers, PCs, game stations (well, they work, but not much fun playing alone), even our room-2-room pager and music system requires a network (for the remote to work).
4) a car. OK, not exactly a "gadget", but it would be a real pain in the ass to walk 4 miles to the closest grocery store/convenience center, not to mention lugging my stuff around, and the 15 minute drive to work would really be a bear on a bike. There's no mass transit here, and a cab ride to work an back is $65 a day (had to do that once, now I rent a car if mine's not working, or actually, the dealership rents me one as I'm now in a nicer car with a warranty).
5) personal gadget: smartphone. It;s not the phone itself, nor the games, or other trinkets I really use it for, and I can live without getting e-mail constantly, and I hate TXT messages; but really it's about my schedule, to-do lists, tracking important stupp and people. Really, the traditional PDA features of the device. Yes, i could bypass this need by carrying around an old fashioned filefax, but those don't auto-notify you of important stuff, and knowing about a meeting does not mean I won't MISS IT if I don;t get a "ding" a few minutes before it starts... goes to the whole lack of job = lack of life motif.
6) Air conditioning: I live in SC. Not only is it rediculously hot, over 90 degrees nearly half the year's days, but humidity is also rediculous! If I had to keep windows open all the time, and fans running, it would put a serious hurt on my system overclocking ability, and the humidity and condensation issues would kill my systems in a single summer. Half my personal devices and gadgets don't do well over 100 degrees either. I had a 3 week span a few years ago where the AC blew out during a summer heat wave and the landlord practically had to have the whole house rebuilt to fix it (new unit, major renovation in attic for 2nd half of unit, reworking ducts, new elecrtical work, new breaker box, cost him nearly $20K to fix...) Those 3 weeks, i had nearly $1500 in devices break down, including a nice SLR camera that got infested with humidity, a laptop screen that cracked, and a router that fried in the heat. It was getting to 112 in the house during the mid day!
Pretty much, everythign else I can or have given up. TV, internet, surround sound, most other luxuries. So long as I have books, electricity, food, cofee, a couple of appliances, and a roof, plus the above "necicities" I'm good.