IMO, Lego sets are far more creative in their themes and design 15 years ago when I was young.
That sentence is broken and you should fix it.
Anyway, There were cool lego sets when I was a kid playing with them (good lord, I probably got my first lego set 20 years ago! I'm too young to be old!), but there is some really cool stuff now.
What Lego has accomplished with Mindstorms is truly commendable. I can't imagine a toy more awesome that even remotely holds a candle to the educational potential of a mindstorms kit.
The technics kits have just been getting more and more awesome. I had the original Mindstorms growing up, and it was pretty awesome, but the number and types of sensors available for the current generation kit is really impressive.
That said, I do agree that their normal kits are more and more 'connect these three unique specialized blocks and call it a day' than when I was a kid. I had friends that would build the model and put it on their shelf forever, so I suppose this change wouldn't affect them at all, but I'd build the model to see it, and then tear it apart and the pieces would go into my giant bins for later use.