The Brookhorse is kinda neat. While I'm not fond of horses on their own, the idea of this horse tricking you into coming into the water is kinda creepy and hilarious at the same time. I seem to remember if you don't fall for its drowning act, it just sort of stares at you.
I -love- Yulecat, which is Icelandic, which is a giant cat who will eat any children who don't receive clothes on Christmas. So if you don't give your kid clothes on Christmas, you are essentially offering them up. I just wrote an episode of a radioplay I'm involved with about Yulecat.
While I can't think of a specific Irish tale, I do like there are quite a bit of stories that are modern about the Fair Folk and the superstitions that surround them. Such as the one about calling them something else because you don't want to offend them.
Japan just has neat weird monsters. Kappa, the haunted umbrella and lanterns, etc. Also a lot of their ghost stories have vengeful spirits which aren't done away with appeasement. They just -hate- the living it seems like.