Assassinated By: Members of Nicky's own crew
Cause of Death: Beaten with metal baseball bats and then dumped in freshly-dug graves

In Martin Scorsese's Casino, Joe Pesci doesn't just get "whacked" with a metal baseball bat—he gets beaten to a bloody pulp. When the Santoro brothers naively show up for a meeting in a desolate cornfield, they're ambushed by Nicky's (Pesci) own crew, who arranged a deal with the mob bosses to kill the hotheaded Nicky in exchange for clemency.

First, they go all Albert Pujols on his brother's face as Nicky watches, and, as if that wasn't message enough, they give Nicky a few more home-runs swings. Then, while they're both still breathing, Nicky's former associates dump the two batting-practice-dummies into freshly dug holes and bury them alive. A simple whacking would've worked just fine, but what do we know?