Tiesto has gone downhill massively over the past couple of years.
I remember seeing him back in 2004 at Cream, Ibiza. He was immense back then, and all the live sets I used to download around that time were the same; quality trance. His 'In Search of Sunrise' series is brilliant, basically a bible of proper trance music, I still listen to all 7 of those regularly.
Saw him out in Ibiza during the summer at his own night at Privilege. Weren't impressed by his set at all... La Roux, Kings of Leon?! Also saw him at Creamfields last month, a very similar set to the one he played in Ibiza, and again it was filled with commercial rubbish (ok, he did drop possibly my favourite trance track of all time, his mix of Silence... but still!).
It's a shame he's become a sell out. He clearly has the talent and know how to be the best DJ in the world, he's just decided to go down the mass produced rubbish road now and rake in the £££'s.