However, when it comes to the live semi-finals, the show morphs into an entirely different and much more enjoyable beast. Tears, bust-ups, disastrous novelty acts who don't seem quite so funny second time around and Walliams prancing around Cowell like Frankie Howard on speed.
Unlike The X Factor it is nigh on impossible to predict the results on Britain's Got Talent. Susan Boyle and Ronan Parke looked like dead certs to be singing for the Queen, but came up short in their finals.
And who makes it through from the semi-finals is even harder to predict. The luck of the draw - the first and final heat are usually the most competitive - and whims of the voting public mean that one botched song choice or production decision can cost you dear.
On X Factor, acts build up fanbases, they can be saved by the judges and the best acts can afford to make a few slip ups and get away with it.
On Got Talent, most viewers have forgotten about the auditionees by the time the live shows start and it truly is a case of perform or face the axe. It doesn't matter how lovely your vocals were at that first audition, you need to nail it at Fountain Studios on a cold Tuesday night in front of 10 million viewers. No pressure.
Attraction are the obvious favourites to win the £250,000 prize this year. The shadow theatre act managed to combine dance, novelty and a story about war, death and young children left without fathers. It ticked all Cowell's boxes for emotional heartstring-tugging and has had over 16 million views on YouTube.
Whether the act can devise two more shadow theatre performances that can have a similar impact on viewers is the nagging doubt surrounding them. Were they just a one-trick pony? Plus, they are Hungarian. The Daily Mail brigade won't like that. Nigel Farage will probably storm their live show and drag them off stage.
The only singers that have won Britain's Got Talent are pop-opera belters Paul Potts and Jai McDowall. Traditional singers like Aliki Chrysochou, Alice Fredenham, Alex Keirl, Jordan O'Keefe, Rosie O'Sullivan and Robbie Kennedy can all expect to reach the semis, but their chances of winning look slim. Viewers tend to look at the singers and ask the obvious question: "Why not X Factor?"
Which is perhaps why acapella group The Band Of Voices and former buskers Luminites stand a better chance than their musical rivals. They have a novelty factor that suits Got Talent and over the semi-final and final, they will still have a surprise element that a solo singer can't possibly deliver.
Hosts Ant & Dec and More Talent presenter Stephen Mulhern have campaigned for an old-fashioned British variety act to win the series for years, but comics, magicians and impressionists have usually been given the cold shoulder by Cowell. Could 2013 be the year for that to change?
Francine Lewis and Philip Green will have to duke it out for the prize of best impressionist if they both make the semi-finals and whoever proves victorious could be a serious contender. Francine is a serious pro performer and she should have enough impressions up her sleeve for two different live performances - so don't rule her out.
Young comic Jack Carroll managed to break two rules of Britain's Got Talent in his first audition. 1) He was a good child act. 2) He was a good comedian. If he's got enough original material for a semi and the final, he's a serious contender to win the whole competition.
My only problem with this year's semi-finals? There's no dancing dogs! Call me a traditionalist, but it isn't BGT without a poodle doing a cha cha cha. Hopefully Cowell has been saving a booty-shaking pooch for this weekend's final auditions show. Paws crossed.
Who do you want to win Britain's Got Talent? Let us know below!