Fullmetal Alchemist

Episode 8
Hughs says that he could have been in a nice bath with his daughter but had to be at the incident instead.

Episode 41
Edward Elric notices that Lyra is wearing perfume and she says that she has to since bathing is a rare luxury in Liore and that she hasn't gotten the chance to bathe in a while.

Episode 44
Winry Rockbell has a bath in Rose's Clawfoot Bathtub while the Shower Curtain is closed. At the beginning Winry stretches her arms out mentioning that she hasn't had a bath in a long time. On the other side of the curtain Rose comes and drops off some clothes for Winry. While still laying in the bathtub Winry says that she is worried about Ed and hopes that he is okay.

Later on the episodes eye-catch shows Winry in a bath poking at a Rubber Duck.

Trivia

 * This episode's title is Revving at Full Throttle (バリンバリンの全開 Barinbarin no Zenkai) and first aired on February 14, 2010. It was first shown in english on Cartoon Network's Adult Swim block on May 8th, 2011.

Fullmetal Alchemist: To the Promised Day
The game has an Onsen scene.