Watching the Kofi/Cesaro match from RAW, it reinforced my belief that Cesaro's European uppercut should be enough to put an opponent away, especially when he does it while diving at his opponent or while the opponent is coming at him, either from the turnbuckle or when Cesaro launches him into the air and then catches him as he comes back down.
Can you think of any moves (current or from days gone by) that by all rights were believable as finishers (both in terms of impact and visual presentation) but aren't? I think Cesaro's Eurpean uppercut is a perfect example of something that fits both criteria, since he delivers it with believable "oomph" while it at the same time is visually stunning and can come from out of nowhere.
Ooh, intriguing one. Although in "yesteryear" guys would beat jobbers with all sorts of crazy shit just for fun, so generally any wacky move you can name has been a finisher at some point.