Ghost of Bugsy Seigal

On the evening of June 20, 1947, gangster Bugsy Siegel sat reading the LA Times in the Beverly Hills home of his girlfriend, Virginia Hill, when an unknown assailant fired nine shots at him through a window, two striking him in the head. Siegel got whacked, gangster-style, probably for cost overruns, skimming from the budget and other fraudulent activity during his involvement building the famed Flamingo Hotel and Casino, which is the oldest remaining casino in Las Vegas. Siegel's spirit has been seen in the house, reportedly ducking for cover from bullets, but the strongest sightings are in the place that probably did him in - the Flamingo Hotel.

According to Prairie Ghosts:

Bugsy is believed to haunt the Presidential Suite of the hotel, where he lived for several years before his death. Guests in this room have reported a number of strange encounters with his ghost, from eerie, moving cold spots to items that vanish and move about the suite. They have also seen his apparition in the bathroom and near the pool table. Those who have encountered him say this spirit does not seem unhappy or distressed and in fact, seems content to still be around. Perhaps he is just happy to see that Las Vegas has turned out the way he had planned after all!