I'll say fallout 3. It wasn't really beloved but its the only game that qualifies for this question since i don't really hate any games i used to love. I went through it (mostly story a few side quests, really just scratched the surface) and was right at the end of the story and my friend erased my save. This has since caused me to really just lose all interest completely because i wasn't that captivated by it to begin with. its an excellent game, but i guess im more of a jrpg fan haha.