Too quick and painless.
[sarcasm warning]
I think he should be eaten by fire ants, or roasted on a spit, or forced to eat fifty bushels of garlic followed by sixty bushels of jalapenos, or eaten by a slow crocodile, or hung upside down from his sensitive areas, or executed by 12 boys with BB guns and as many BBs as it takes. I think he should be coated with gravy and thrown into a pit full of hungry puppies. I think he should walk on cobblestone streets in 5-inch spike heels. I think he should spit on the bride at a Mafia wedding.
/sarcasm, maybe.
LOL - All sound like good options to me!