It's all what kind of soil you have, and how or what you use it on.
For me it was the Box Scraper.... When I got it all I had was a Cub Cadet 1641 (hydro 3pt)... that just killed the little tractor when only 1/2 full of dirt! Wheels a spinning and the tractor didn't have enough power to lift the BS up when 1/2 full... had to get off, and scoup out the dirt...
Gave it away to someone that had a tractor but only a
FEL. they found they needed weight on the back... and the BS came in nice as counter weight and the tines helped him dig.
For me I got a 72" LP Tilt and angle blade that I have found tremendously usefull!!!
Oh then there is the little land scape rake that i bought for the 1641..... Yea, does anyone want a 0- 3pt 4' landscape rake.... It's too smal for the Kubota...
I use everything else and wouldn't part with any of them!