18" AK for chopping; replaces axe, hatchet, saw, hammer, wedge, prybar, adze, chisel, rasp and tomahawk. Ideal for lopping and felling timber, splitting firewood and beheading small to medium dragons.
20" sirupati for everything else; will also lop, fell and split wood, but you need to hit harder and more often.
18" GS (Gelbu Special); good compromise between the AK and the sirupati. If you're really *really* only gonna have one, the GS is probably the one to choose.
For excellence of ergonomic design and sheer sexiness, the YCS is hard to beat.
Or, as the RCBS folks used to say; "Might as well start off with what you'll end up with", and go for the ultimate do-it-all superkhuk, the 25" Kobra. But then you'd miss out on all the fun of owning and using a dozen or so other HI models along the way...