Think this way about tools. NEVER EVER EVER buy a cheap tool, it will cost you far more than you ever saved by being cheap to buy. cheap pliers slip and mark fittings, cheap wrenches round over nuts, cheap screw drivers slip and gouge finished surfaces. etc etc etc, If you are buying a cordless drill, pay 120 to 200 for a good one, they will work better, by a contractor grade anything, and do not ask the guy at the counter, but look at what contractors are buying,
Plumbing tools, Ridgid is still the name, even though Home Depot owns them they still are the class of the trade.
electrical tools, Klein. buy some basics and learn how to swap out a bad outlet or switch. save you thousands in a short time. vs paying electrician for same.
Power tools, makita, Bosch, Hitachi, milwaukee. at minimum a 12 volt cordless, at most a 14.4 V system, any less not strong enough, anymore too heavy for most. I currently use and really like the makita 12 volt 2.6 amphour tools, light, strong and long lifed, Stay away from Dewalt cordless, they have very short battery lifespans, and lousy customer service. Some prefer the panasonics and the FIEN tools, they are good, just not what i am used to.
Ladders, Buy only grade 1A ladders. buy a couple of good ones on sale. if you can find an electricians platform ladder and a twin step, you will be happy, also find a three foot folder that can go in your trunk and get you up to lights, etc inside the house and do it safely. One fall from a wobbly weak III ladder and you understand that extra 50 bucks is dirt cheap
hand tools, Craftsman used to be the bottom of the acceptable limits, now even they have fallen so far as to barely make the threshold. MAC and snapon are worth what you pay.
Painting stuff. Buy good extensions, brushes and rollers, Go to a painting contractor supply store and ask for contractor rollers and covers, the difference is amazing. for Drywall/plaster, walbord and Goldblatts are the names. Get a rock square too, just a 4 foot T square, but useful for all sorts of things.
carpentry tools. depends on your skill levels. buy a good level, a swanson speed square, a framing square (aluminum) a good hammer, I prefer Harts, a set of real Vise Grips, a set of real Channel lock pliers, a stanley or vaugh wonderbar. no reason to buy a hand saw yet, I would suggest a Sawzall and then a good circular saw when you get better aquainted to the job. Two Chisels, a 1/2 and 1 inch to start. ONLY use them to remove clean wood, they are not prybars not staple pullers. A stanleyknife with extra blades. a hacksaw if you do not get the sawzall.
I carry most of my service call tools in two containers, one is a Big Mouth bag and the other is a bucket boss bag that hangs on a five gallon bucket. with these two sets of tools I can fix 90% of face problems with out needing more.