Here's what I've figured out so far. I am pretty hard on my tools as I use them on my own stuff and at work in the service department of a factory dealership.
Screwdrivers; buy the cheapest ones you can find becuase you will end up using them as prybars are tearing up the tips on stubborn screws. Snap-On sells a set of eight (sdgx80) for $127.00, I buy from the bargain bins at Napa or Wal-mart for less than a buck usually.
Sockets; I am slowly replacing my Craftsman sockets with Snap-On and Mac. I've seen too many split walls on the standard and impact drive sockets on the Craftsman stuff. I've also seen the drive end of the Craftsman impact sockets become loose after it is used long enough with air tools. This doesn't happen often but I can't afford to be without some sockets sizes at work, even for a day. All my 1/2 inch drive stuff is Snap-On or Mac.
Socket Wrenches; Only Snap-On, maybe Mac. Craftsman ones keep breaking on me, the ratchet mechanism just isn't strong enough. I can't think of three different Craftsman socket wrenches I bought new that have broken (two 3/8s drive, one 1/2 inch drive) in normal use.
Wrenches; I have a full set of Craftsman wrenches that work fine. I don't feel bad about using a cheater bar or a

on these. I buy Snap-On when I need a specialty wrench; but I don't abuse them like the Craftsman ones.
Ratchet Wrenches; I have a Snap-On brand that work great and are not heavy at all. These are great to have and handle all the force you can put to them. I wouldn't trust the unheard of brands, I've seen the ratcheting mechansims fail on these more than a few times.
Torque Wrenches; Beam Style is alright but slow when there are alot of bolts to turn. I have a 3/8 drive Snap-On thumb wheel version (very similiar to TQFR100E) that works great. The thumb wheel is turned to select how much torque to transfer and you just turn the bolt/nut till the wrench clicks. This wrench is a step above the twist handle styles. I have a beam style from Craftsman but don't hardly use it anymore. Buy the best quality torque wrench you can. Not sure about the beam style but the twist handle and thumb wheel versions can be recalibrated.
Hammers; Learn how to properly mount a head on a handle and you'll be set for life. (Same theory also applies to picks, axes, pulaskis...) Use good quality handles and don't forget to set the grain of the wood so that it is perpindicular to the striking face of the head. Handles break but heads are hardly ever damaged beyond thier usefullness. I keep a few sizes of ball peen, a large and small claw

, a couple sizes of hard plastic and rubber mallets and a small set of body

s and dollies. Never use body

s for anything besdies bodywork.
Air Tools and Compressors; Ingersoll Rand, Snap-On and Mac all make very good air tools. Craftsman are ok, but seem to fail far more than others. Buy the best quality and largest compressor you can afford too. Don't buy a small compressor. Ingersoll Rand and Emglo (who maunufactures compressors for Dewalt) make very good stuff. I haven't seen a compressor that didn't work well yet from any manufacturer though, even off-brands.
Welders; Miller, Lincoln, Hobart... these are all very good brands; the industry standard I should say. Just compare similiar models and talk to the experts to find what is right for the application and your own skill. I have a Lincoln 100 amp wire feed welder that works great. I recently bought a very old Montgumery Ward 100 amp stick welder. It works good, and for $50 it came with a hood and a few pounds of rod. Why I bought it; it fits my ability and gets me practicing my stick welding.
Toolboxes; I have a Mac Toolchest at work (about four feet long, two feet deep) that holds the tools that I use there. Mac, Snap-On, Craftsman (with the roller bearing drawers) are all good. I have the three drawer Craftsman tool box that I started with as my go between work and home. Check pawnshops and tool dealers for used toolbaxes; high quality can be found. My Toolchest goes for around $3000 from the tool dealers; I bought it used for $500. It is in like new condition, but I also know the guy cut me a really good deal.
Things to Remember; Not all tools have to be expensive to be good. I only buy Snap-On when I need something special or immidiately. I avoid buying Craftsman tools that have moving
parts; no socket wrenches or air tools. Garage sales and pawn shops are the best places to find great deals on tools. Make a list of every size and shape of tool that you need on your three-wheeler and pick what you need up from the pawn shop and make a trail set of tools. Tools can be made, I've cut pipe to make specialty sockets and used a grinder to make a 23mm hex out of an axleshaft. I also have a few wrenches that I've bent or cut to fit in certain places. I make funnel out of oil bottles at work and cut the square wiper fluid bottles in left and right halves to get two trays for holding
parts as I work on things. The boxes from oil filters; cut off the tops and staple about six together to make a nice organizer for nuts and bolts.
I am just starting out (I'm only 23) but I figure I already have around $8000 worth of tools. This is just basic tools that get me started. I am still short on alot of things but have everything I need for most jobs. Never borrow a tool without permission, and return it as soon as you're finished with it; make sure it's clean and if it's damaged let the person know. By looking for deals and being creative I probably have only a few grand invested.
More important than the tools, is the knowledge of how to use them.