I do love spore a lot, I remember begging my mum for it when I was little and when I finally got it on my birthday, I played it all day and kept playing it. My favourite stage is the second one, the creature stage with my least favourite being the last one, the space age. I also remember preordering the first expansion for the game, galactic adventures which made the space age a lot more exciting, not to mention the world creator where I could spam epic's everywhere XD.
I never actually beat the game as the space age goes on for way too long and even now I find the space age to be very boring. Or maybe I just didn't play it enough to get a good feel for it.
Sadly I don't play it as much and can't get as much excitement from the game as I used too but it's still fun to create creatures. I remember hearing that the game was going to be completely different before it was released with there even being another stage where it's basically the creature stage but you're still in the ocean.
(RIP Maxis)