This is an unpopular opinion, but I've always found Giacchino's film scores forgettable.
His Lost soundtrack is incredible, but I can never recall a single one of his film tunes. What's funny is I know there are a few Giacchino tracks where I can remember thinking were catchy -- like his Star Trek theme or Doctor Strange theme -- after the movie ended, but with some distance I can't for the life of me actually remember what they sound like.
His Up and Ratatouille scores are also incredible.. but yea, Lost remains his best work to date.