Yes, it's Hekker.
Greatest punter, single handedly saved us in several games with his foot and arm during the Fisher era.
Close behind is Wilkins who caught his own onside kick in the playoffs vs the Panthers and was always "money" whenever we needed him. (I met him and Dane Looker at a golf course near Branson, Mo. - they were super cool)
The Leg is tied with Money.
But, there is another.
Anyone remember the Fitzmagic debut against Houston? Down 2 scores and 2 QBs, the Rams needed more possessions.The Reverend Isaac Bruce put himself in on the kick coverage team, ran down the field, found the returner and forced a turn over, just like that. Because Isaac Bruce was a mother fucking Jedi Knight and he could do that kind of shit.
So, final answer: Bruce, because if he had wanted to be the Rams greatest STs player of all time, he would have been and nobody could have stopped him.