Ah.Nutcracker is awful, in that case (Murphy's Law and all that).Poor you!
But seriously,it's extremely popular as an introduction to ballet and the story is particularly enchanting for children.It has a children's theme.
Giselle and Swan Lake have themes which mean a lot more to adults; love and deception, betrayal; which are lost on youngsters though the ballets can be seen simply as fairy tales with lots of ballerinas in tutus.Giselle is the shortest ballet in the classical repertoire (a plus?).It needs a very good actress in the lead,good dancing is not enough.Swan Lake has very impressive music (Tchaikovsky's grandest and most dramatic tune figures).It has two alternative endings; we dance the more tragic one,Russians dance the happier one, courtesy of Stalin , who wanted happy endings ! Swan Lake is more popular, but I rate a good Giselle to beat anything.