I'm pretty much alergic to hand tools! lol They are waaaaaaaay too much work and time consumeing for me... I don't have any weeds in my gardens to speak of, so no handtools to keep them out! I got all of that i wanted when i was a kid! BEFORE i learned to deal with them!
SO, i'd have to say this,
is my most useful gardening tool
I bought it new in 1986 for $5,200.00 bucks and other than maintance, it's cost me about nothing to own since then! What a bargin, as i think it will last until i can't look over the dirt i till! Best part is, i've probably made over $5200 with it mowing grass and tilling gardens!
BTW, that's a Howard Rotavator on the back and it cost me nothing but the $1,500 i paid for it back in about 1986 or so? It's also paid for itself and what a fantastic job it does!!
SR