Lets be honest...CBB usually have great lineups
 

Just watching I'm a Celebrity, and even though I know most, it's not a very good line up. CBB9-CBB14 have had very good lineups in comparison to other reality shows. And it's more impressive when you know that IAC gets much more exposure (quadruple the ratings), but CBB still ends up getting great people on a much smaller channel.

The way that everybody goes on about CBB as 'scraping the barrel' yet I can't remember the last time that I'm a Celeb had some amazing cast

CBB aren't stuck up about their celebrities, meaning they end up getting the most entertaining one's. Frankly, the producers don't give a crap how famous they are as long as they're a Z Lister. IAC usually only go for comedians/Olympians/actors and actresses.