If we went by campmates who have gotten the maximum amount of stars available, here is a list of contestants that managed to get every single star on offer in their series. (this includes double trials). People like Myleene got all of the stars individually, but didn't when paired up. Joe Swash only missed 1 star out of 7 trials, making him one of the most successful campmates ever.

These are the only people who got 100% success rate and won "battle offs".

Catalina (S2)- Only did 1 trial though
Bobby Ball (S5). Did 2 trials.
Anna Ryder Richardson (S7). Only did 1 paired trial
Shaun Ryder (S10) got maximum stars in all 4 trials he did, 5 including the 2 way battle where he won against Gillian.
Emily Scott (S11) got maximum stars in 1 trial.
Rebecca A and Alfonso (S13) both got maximum stars in their trials. Rebecca in her 2 and Alfonso in his 3.
Jake (S14) got maximum stars in his 3 trials, and won against Foggy in the head to head.

Very special mentions:
Robert Killroy managed to get maximum stars in his 2 trials but lost in a 2 way battle against Joe on one.
Foggy managed to get the maximum stars but lost 2 way battle with Jake.
Timmy Mallett won maximum stars in one of his trials, but lost in a 2 way battle against Brian Paddick.

So Shaun Ryder, Alfonso R and Jake are actually the Top 3 most successful campmates ever, and a very special mention to both Foggy and Joe Swash who did the most trials and got a huge amount of stars.

So in terms of performance, last nights final 2 would be the best in IAC history.

However Shaun Ryder did 4 trials, and Alfonso and Jake 3.

So isn't Shaun Ryder the most successful campmate across all series?

Yep, that's right.

1. Shaun
2. Jake (ahead of Alfonso because he won an extra head to head)
3. Alfonso
4. Foggy
5. Joe Swash

Actually I missed a part, Joe lost once against Nicola as well as missing that star I said. So yep, the Top 5 I'd say would be correct.

My memory isn't good enough to single out the most difficult trials ever. Wikipedia singles out Joe Pasquale's 'Hellocopter' as "the most dramatic and expensive trial ever", but I don't even remember it.

This doesn't really fit in here, but I am interested to see that Australia are doing their first ever IAC next year, and not surprisingly, it won't be held in Australia...

Salv, how the hell do u know this stuff?

Wiki is your friend. They are always great at reality stuff.