First Place: A pickup truck. Absolutely essential. You cannot build something like this without one. Best tool ever. Once you own one, you'll never be able to live without it. You'll begin looking down your nose at the smooth-skinned pansies who drive around in European sports cars. You pity the guys you see at the dump who have to cram their garbage and yard waste into the back seat or the trunk. You'll also suddenly be the best friend of anyone who doesn't have one, unfortunately.
Second Place: A gas nail gun. Nothing will make framing go faster. The best tool I purchased next to the pickup. And it's like a gun, so it's got that going for it.
Third Place: 12" Compound Mitre Saw and stand. You cannot live without this for any kind of roof framing, and - as a bonus - it makes quick work out of walls, siding and trim.
Fourth Place: Clamps. From quick-release to pipe clamps, these are essential to working alone, taking the place of the slave labor you couldn't find.
Runners-up:
- Heavy-Duty cordless drill
- Corded drill (because your batteries will run out, and you'll need it while they're charging)
- Hammers (for small nails, and for when the gas nailer decides to go on vacation for no good reason)
- Ladders in various sizes, from a step-stool to at least 24'
- Speed Square (you'll be amazed at how much you use this)
- Power Saw
- Hand Plane (don't let Norm fool you - not all the best tool have power chords)
- Assorted Screwdrivers
- Tape Measures and Pencils (the more the better, as they are always getting misplaced)
- Chalk Line
- Pneumatic Finish Nailers and Portable Compressor (a second-place winner for trimwork or cabinetry)
- Levels in various sizes, from 4" to 5'
- Compass (the pencil-and-point kind, not the directional one)
- Chisels
- Paint brushes
- Sawhorses
- Japanese saws - small and large (cuts on the pull rather than the push)
- Hand Saw
- Cat's Paws in various configurations
- Nail cutter
- Socket set or wrenches
- Vice grips
- Pliers
And to hold it all: A good-quality tote and tool belt.