Out of the current lot, i would argue Billy and Bash deserve the tesimonial. I think Billy might even get a stand/statue one day.
I actually think Didzy should have a testimonial too, i know he hasn't been at the club all that long, but he is another who personifies the Sheffield United spirit, he fights tirelessly and is never under a 6, even on the darkest days, leading from the front. He is an inspiration to everyone, how he has never given up with us, in his career and the injuries he has overcame to get to the top flight.
Big question is, would Jags qualify for testimonial? he's got the games under his belt... but the whopping 322 games spent at Everton might say differently... (would love to see the Warnock team back together just for laughs)