Guardians of the Galaxy - The voice actors are the worst. The repetition and just generally boring game play are a close second.
Star Wars Episode I - Just annoying and stupid. The gimmick gets old and RFM does it better.
South Park - Is any explanation needed? It's just terrible.
Bonus: Game I think is overrated: Attack From Mars
Bonus: Game I like that most hate: Street Fighter II (though not enough to not sell it)