You can also apply this to games, take FFXII, it hinted at a romance potential several times in the game but never did anything with it. Your reference to Last Exile wasn’t that bad for me IMO, I guess because I cared more about the other characters as apposed to Claus (Alex and Dio). But the FMA is right on, they it was just really messed up how the series ended (check out my response to that ending --> Here Warning of spoilers). Trigun is also like that given they really never develop Vash’s romantic relationship with Meryl. But the worst one I have ever seen has got to be Gungrave. They for episode after episode apply so much focus on Brandon’s love for Maria just for him to never take her.