Lust
Because it existed in Clove in every way possible. The lust for power and the lust for glory being at the top of her list. Until she saw the girl from 12, and the need to tackle her to the ground of the training room and shower her with a million kisses, outdid all other needs.
Gluttony
Because Clove didn't care who was starving in the arena. The careers had the food supply and that was that. When lover girl had decided to blow it all up, thats when Clove knew that she needed to prove herself.
Greed
Because before the start Clove had wanted to win, and she didn't care who she would have to kill to get the crown.
Sloth
Because as soon as Clove saw fire girl escape safely, she welcomed her death with open arms.
Wrath
Because Clove absolutely hated the way she noticed whenever Katniss smiled, and despised the way she wanted to smile back. And she couldn't stand the way she noticed how beautiful Katniss looked during the interviews, twirling around in that stupid dress, surrounded by flames. Those weren't the kind of things she was supposed to notice. So she thought she would kill her. Until she realized she couldn't.
Envy
Because the night after Peeta joined the careers, Clove had honestly considered slitting his throat and making it look like an accident. All because he dared to say he loved Katniss. And that Katniss probably loved him back.
Pride
Because Clove would never in a million years admit that Katniss Everdeen, a poor girl from district 12 of all places, had stolen her heart.