(1) It's been an amazing journey
Ah yes, the journey. It is almost impossible to watch any TV show without someone saying they have been on a journey. Yes they have, but mostly just from their house to the TV studio. What sort of journey are we talking about? Well, contestants seem to think that they have had a great many life experiences and had profound truths offered to them through (in the case of something like Big Brother) performing fairly menial and possibly degrading tasks that are of no significance to man nor beast.
(2) I've learned a lot about myself
So, contestant, have you learned anything about yourself from the process? Honest answer: Not really, I'm an extrovert show-off with a self-deluded inflated opinion of my interest to other people and my abilities. Nothing has changed. Forced answer that they feel obliged to give: Yes, I've learned a great deal about myself. I've learned blah, blah, blah and that also I should be less judgemental of others and blah blah blah... empty words... more stuff... blah...
(3) This was the hardest thing I've ever done
Yes folks, I said on my application I've fought in wars and given birth to ten kids simultaneously in the middle of a field, and I have walked over a bed of nails, but nothing compares to this. Those two minutes up on stage trying to sing but failing miserably, or performing some fairly boring task whilst you all laugh at me - that was the hardest thing I've ever done. Either they've had a charmed life or are just lying, but such is the demand to come out with a classic cliche that most contestants bow to the pressure.
(4) I've made a friend for life
In any show where there are other contestants or people are put into partnerships, let's say a dancing show, the contestant who goes out always gushes about how great their partner is. A few years later when they see a photo tthey probably won't even remember their name, but let's not be too hard on them - they probably meant it at the time!
(5) This is all I've ever wanted since I was a kid
... and did I say I couldn't imagine doing anything else? I couldn't possibly imagine going back to my dead-end job after this (what's that employer, you're watching)? I used to be a street cleaner / road sweeper / waiter in a back-end bar / office clerk / civil servant but I've always wanted to be a singer / talent show wannabe and now I'm hear I just couldn't imagine ever doing anythnig else again.
(6) It's been the best experience of my life
Ah yes, the natural opposite to the extreme lows are the extreme highs. Also associated with this one are classics such as "It hasn't sunk in yet" and associated fairly empty phrases. Typically uttered by the winner or a loser who thinks if they are nice to people like the judges they might still have a chance of making it in the future (delusions run deep with some people!)