The Rob Sneed '034' bull - worked well in our commercial herd, over mostly 3/4AN-1/4SM cows. Still have semen in the next-door neighbor's tank, but no cows to put it in...
Used one cane of Captain Obvious semen, but there was no growth there, and got nothing that earned the opportunity to stay - but did have one nice CO daughter that died of tetanus at ~4months.
Always wanted to try some Kaper 4508 and DRC 101VM(Dover)... but never got around to it.
Dragon Lady and the late Dr. Tom Howard pushed me toward Waukaru when we first branched out into using some Shorthorn sires. Waukaru Gold Mine 2109 left some really nice daughters, and was probably my favorite of the Waukaru sires... safe to use on a heifer of any breed. Waukaru Coppertop 464 left some good daughters, too. Steers from both were top-flight.
Waukaru Gold Card, Patent, & Orion brought a lot of growth, but daughters were either too big, or didn't produce enough milk to raise a pygmy goat, and none stayed.