But one longstanding resident at the station who doesn't have to worry about someone swiping his chair is Scott Mills. With three more years on-air guaranteed, the DJ has been focusing on writing his autobiography Love You Bye, in which he relives some of the craziest moments from his time at Radio 1 and opens up about his struggles with anxiety attacks, alcohol and weight issues.
Speaking to Digital Spy, Mills talked about the "stressful" but "therapeutic" process of putting the book together, as well as his thoughts on whether Grimmy will ever be able to win over #TeamMoyles...
What made you want to write the book and why now?
"Everyone's like, 'oh he must be entering this new chapter, which is why he's decided to release this book' - it wasn't even that organised. The [publishers] asked me about a year and a half ago if I wanted to do it and I said no, because I just thought it wasn't going to be interesting. Then I thought actually there's probably some stuff that's fairly interesting to listeners of my show... there's a bit of celeb stuff and I've been quite honest really.
"I'm not sure I would do it again. I found it really stressful at times, like one of the hardest things I've done. I think it's been quite therapeutic to write, but now I've done it I think it's done and it's out there and I'm quite pleased with it."
How long were you working on it?
"Well, I showed it to the BBC and they didn't like it. I kind of enquired as to why and they just said it didn't sound like me. There wasn't enough detail, there wasn't enough emotion, it was a bit, 'that was, this is, then I met Lady GaGa'.
"I was like, 'I don't know what to do because they don't think it's good enough and therefore I should probably rewrite it', and I did in two weeks. It was mental. I didn't sleep. It was really stressful.
"It's a lot funnier now and it's a lot more personal to me. I think with the first one I was probably a bit too scared to write in a lot of stuff. It's like how much of yourself do you want to give away? And I just thought sod it, I'm only gonna do this once, probably, so just say it. It was really hard but I'm really pleased with it."
Were you getting tired of putting on a happy-go-lucky exterior when there were quite a few dark things going on in your life?
"A lot of people on Twitter who have bought it have said, 'oh I didn't really know that about you, I didn't know about the depression or you know, some of the really dark stuff that's happened'. But it's stuff that I would never address on the radio because my show is literally me laughing pretty much for three hours a day and that's what I want it to be.
"It is kind of like laying your soul on the line a bit, but I'm pleased I've done it. It's been a good outlet for it really. It's quite revealing, it's quite honest and that's what I wanted it to be. I didn't want it to be a bland autobiography."
You say in the book that you still can't believe how well your career has gone. Why do you still feel like that after more than a decade at Radio 1?
"I still don't ever feel entirely at ease or comfortable with it and that's a bad thing sometimes. I'm obviously aware of what I've done and I'm aware of how it's gone but I think there's always the less confident side of me that goes, 'oh yeah, but you're not very good really'.
"I think a lot of people in any kind of job like this do have that kind of nagging self-doubt. I think it works in your favour some times, because I still wanna make that show the best show it can be and I think it stops you from becoming complacent."
You have filled in for Chris Moyles on the Breakfast Show in the past - do you harbour any kind of frustration or resentment that the job never went to you?
"In 2007 [a paper] printed that Moyles was being sacked and I was gonna take over. Of course it wasn't true, but I think if that had happened then I would have been really pissed off if I hadn't got the show, because I was next in line for it.
"I don't think I would wanna do it now, I honestly don't. I think the time has gone. I think there was a time period of about two, three, four years when I would have been bang up for it - that time is not now.
"Chris Moyles has been there for such a long time, why would you replace him with me now? Radio 1 is a young station, it's a generational station and age-wise and genre-wise, if you replace me for him you're replacing like for like. Someone like Grimmy is what they need. It makes a statement. I'm just pleased to still be on there and I love it so much still, but do I think I've missed the boat on this one? Not really."
Do you think Nick Grimshaw will do a good job?
"I think he'll do a great job. I really enjoy listening to him. I really get on with him as well and he's really at the radio station properly loved. obviously he'll get a hard time for a while because [he has] massive shoes to fill.
"I think people will get to like it. I think a new younger load of listeners will really like it and, yes, there will be a lot of older listeners who won't like it. But that's what Radio 1's supposed to do. You're not supposed to like it if you're 45."
Have you thought about your future at Radio 1?
"As long as you're still in touch with the audience, you can still get inside their heads and you're saying stuff that they relate to, then I think you should be on there. The moment that stops happening to me, I don't want to be on there.
"I've just signed up for another three years, but after that time I will probably be too old for it and you've got to move on. It's the same with the listeners, I think it's hard for people to go, 'well, maybe I am too old for Radio 1 now', but there's a reason why you don't like it. It's because it's young.
"I'm just realistic. By the time I finish Radio 1, if it is [after the deal], it will be something like 16 years [on air]. I still love it, but it is moving into a different generation... that's not a bad thing."
How was it saying goodbye to Moyles?
"It was weird and very emotional because he's been doing breakfast for a hell of a long time. I thought [the final episode] was really well done by him, I think he handled it amazingly well and really professionally and it was actually quite an emotional listen I thought."
There was a story published recently where you admitted to being scared of Moyles when you first joined Radio 1. Did he know you felt like that?
"I know him really well now and I told him years ago that he scared me at first. It wasn't like he was a bully, but during that time he was kind of self-confident and quite egotistical. He was a young, rising star and he wanted you to know that, which I totally get.
"He's completely changed as a person. He became more mellow and more relaxed with himself and his show. There was a time when he would pick on everybody and I was just one of them because I was new boy.
"When you start working there, [you are] terrified. It's scary, because you don't know anybody and you're the new DJ. I remember sitting in the office at Radio 1 for about a week before I went on air and they all thought I was work experience. And that's why whenever a new DJ joins now I'm super nice to them because I remember how horrific it was just trying to fit in."
What would you say is your proudest moment at Radio 1?
"I always really enjoy like when we do the Edinburgh Festival shows. We started doing that in 2009 and we did this thing called Scott Mills: The Musical, which is complete mickey take. It was the most fun ever. Actual proper actors and singers singing songs about you is really weird.
"I remember feeling really proud of when Robbie Williams did those Knebworth shows quite a few years ago and they asked me to do the coverage for that. I remember thinking to myself, that I'd done a really good job on that.
"And also I still get really proud about the Radio 1 big weekend. A lot of radio stations do festivals or events now, but I still don't think anyone can get the lineups like Radio 1 can. The fact that we can bring Lady GaGa to Carlisle or Madonna to Maidstone is pretty bonkers."
How do you deal with those awkward on-air moments?
"You just do. I get asked that quite a lot and there's just some kind of autopilot mode you go into when you just cope with it, because what else are you going to do? You can't fall apart because you're live on air.
"It's happened to me a lot with difficult people or people that don't really want to be there and are making it quite obvious, or situations like that when they just walk out. A lot of it is just blagging it, to be honest. I just seem to have this inbuilt thing where I can genuinely pretty much talk my way out of [awkward moments], but sometimes it's really stressful."
One of the most popular features on your show is 'Innuendo Bingo'. Have you thought about taking it to TV?
"I'm not sure if it will work as a TV format, because it's kind of the same every time. But I think if you're listening and you can watch it at the same time it works really well. At the moment you can't watch it on your phone, but I think soon you'll be able to and actually, once that happens, everyone will watch it who's listening I think.
"That only started as a little thing probably two years ago and now it's grown into the most popular thing on the show. People send in ideas for it every day. Most of my emails are about 'Innuendo Bingo'."
Would you like to do more TV work?
"I like doing TV and I do enough of it to enjoy it. I did this Uganda documentary [The World's Worst Place To Be Gay] that was really serious, but I was really proud of that. I think it's one of the best thing's I've done. And then it's generally quite light fluffy stuff like the lottery or going to live with The Hoff.
"I quite like doing it - I would never replace radio with it. Radio is what I've done since I can remember really and I've never thought I would be on TV. It didn't cross my mind. So I like doing it but it's kind of my little hobby."
Mills's first autobiography Love You Bye is on sale now.