I always liked those cages they'd hang up from poles on the main road just outside of town. The iron ones that are a little shorter than the person but too narrow to sit down, and not enough space between the iron bars to stick yer legs through. So you get to die of thirst while crouched over just a little bit, hanging up about 20 ft in the air. Impressive, very public, and it sends the message that murder just isn't acceptable here.
Although there is a lot to be said for a a quick, painless, and relatively anonymous execution. The trouble is that it takes so darn long nowadays that it becomes personal again instead of a clinical application of the law.
It's gotta be fair and the system has to make every effort to keep innocent people from being executed, but it shouldn't take 10+ years to execute someone who is guilty beyond any shadow of a doubt. Only the lawyers and the perp get anything out of that.