Here's what the judges had to say:
Girl Band - 'Venus'
Dannii: "I think that's the campest opening to the show. I'm not sure if it was Brian [Friedman] or Louis, but it definitely was the campest opening to this show ever. I loved it."
Cheryl: "You definitely had the hardest job of all. First act on, I thought you did a fantastic job of it and I really enjoyed it. Great song choice."
Simon: "I thought it was OK. [It was] a predictable song, very predictable styling. If I'm being honest with you it was like a Girls Aloud bunch of rejects... I've seen all this a million times before."
Scott - 'Yeh Yeh'
Louis: "Scott, you're a really nice guy, you work really hard [but] I don't understand where you got that song from. It's the most hideous song choice ever on X Factor. Scott, I'm not blaming you, I'm blaming Simon."
Dannii: "Sack your mentor! That was not the right song for you. Everything you've brought to this competition you've done right [but] that was not the song for you."
Cheryl: "You are a really thoroughly nice guy. I see where Simon was going with the song choice. I think he was trying to separate you from the bluecoat but in turn he gave you the biggest bluecoat song going."
Simon: "I got this wrong. I was trying to do something different. I give you my word I will give you a better song choice next week."
JLS - 'I'll Make Love To You'
Dannii: "You guys have been hot right from the beginning. My spies at the house tell me that you have more clothes than the girls do! I loved it."
Cheryl: "Guys, you are professional, consistent, the chemistry between you is amazing to watch. That's one of my favourite songs of all time and you're bound to be nervous but I loved it. Well done."
Simon: "It didn't start very well, but I think you knew that. Having said that, this was a crazy song choice. You guys actually look like a group and behave like a group. You have a fantastic chemistry. If you can get this tuning right, which I think you will, I'm going to make a prediction: I think you are potentially the best group we've ever had on this show."
Rachel - 'With Every Heartbeat'
Louis: "You are definitely one of the best singers we've ever had at the auditions for X Factor [but] that was totally the wrong song. I know you'll have the talent with the right song... I just didn't get it at all."
Cheryl: "I think you've got the most incredible vocal, possibly the strongest in this competition, but I think your vocal is far bigger and far better than that track."
Simon: "You know how much I liked you during the auditions. Dannii, you've just given her a hideous song which doesn't match up to her talent. It was like putting lemonade, instead of petrol, into a Ferrari."
Dannii: "We'll get your song choice right but I really want to say thank you for giving it your best shot because that is what proves to everyone that you're willing to make this."
Alexandra - 'I Wanna Dance With Somebody'
Louis: "That was incredible! You look like a diva, you sound like a diva and you dance like a diva. You're amazing!"
Dannii: "You did all of that choreography incredibly."
Simon: "It was a bit of an obvious song choice. Having said that, I think you look fantastic [and] I think you managed to put your interpretation on the song brilliantly."
Cheryl: "You owned that stage tonight. You absolutely tore it up, I am so proud of you."
Ruth - 'Take My Breath Away'
Louis: "It was a very, very emotional, over-the-top diva performance. I liked it, but I'm not sure the British public are going to get you."
Cheryl: "You look absolutely stunning. You had the sensualness [sic] that song needed and I think it was the perfect song for you. I think you did a fantastic job.
Simon: "You have a very powerful presence. What I love about you, which is why I don't think Louis gets you, is that you are a real woman. I don't think you are the best singer, but you have charisma."
Bad Lashes - 'It Must Have Been Love'
Dannii: "I really love the makeover that you've had. The solo bits were really good. There were so many backing vocals in the chorus that it was sometimes hard to hear what was going on. I think the thing that's going to distinguish you from the other girl band is personality."
Cheryl: "I absolutely love you girls. I think you're edgy, I think you're spunky, I love the makeover. I wouldn't have chose that song, though, I would have had you more indie, more groovy. I love you."
Simon: "To me it was like four separate singers singing a song quite well, it got a bit shrieky at the end. I think the fun has been sucked out of you. It was a bit like eating water, it doesn't actually do anything."
Daniel - 'I Want to Know What Love Is'
Louis: "You picked a really good song tonight but for me, it really didn't work. It was very cruise ship. In fact, you remind me of Ricky Gervais singing karaoke at a Christmas party. It didn't work for me at all."
Cheryl: "I think you're a lovely guy. You look gorgeous in your suit [but] as a recording artist, I don't quite know where you'd sit."
Simon: "I really, really like you [but] it was like someone singing in a pub. You cannot win a show like this because I don't think you would ever be a successful recording artist."
Eoghan - 'Imagine'
Louis: "I like you. You've got so much potential and you're going to go a long way in this competition."
Dannii: "That was so good. You are just sailing towards the final. Youngest performer, most mature performance and do you have a girlfriend?"
Cheryl: "I was slightly concerned when I heard about the song choice because it's such a big song but you absolutely nailed it. It was amazing."
Simon: "What you did tonight just worked. You got it absolutely right. I am very, very proud of you, Eoghan, after what you did tonight."
Austin - 'Every Breath You Take'
Louis: "You look like a pop star tonight. You are a fantastic singer. You've got a very soulful voice and if you can keep it together you'll go very far in this competition."
Dannii: "You do nervous sexy. If that's your first performance, it's unbelievable what we're going to see. I think that was the perfect song for you. I loved it."
Cheryl: "Faultless vocal and you looked like a pop star tonight."
Simon: "It was good. That was 60% of your total ability, but I know there's a tonne left in reserve."
Laura - 'Fallin''
Louis: "I cannot believe that you're not confident. It was definitely one of the best performances of the night. That was just incredible."
Dannii: "You are a major contender. I loved you from your very first audition - you're just the bomb!"
Simon: "I genuinely wasn't sure whether you were going to be able to cope with all this tonight, Taking all of that into account, I thought that was outstanding. You have something very, very special. You have a fantastic future, potentially, ahead of you, young lady."
Diana - 'With Or Without You'
Louis: "You are actually a breath of fresh air in a competition like this, because you're cool, you're contemporary, you're real. I think you're the one to beat in this competition."
Dannii: "Diana, you went flying into this competition from your first audition. I'm not sure if there was too much hands sometimes, you look like you're doing a puppet show and it distracts from your voice which is beautiful."
Simon: "You are like the singing version of Marmite, in that [people] will either love it or hate it. I loved it. It wasn't a perfect vocal. Singing that song was a massive risk, I actually thought it was fantastic."