If you just spoiled yourself on GLaDOS trying to kill you, then yeah, it's still worth it. I mean that's always a possibility when AI is involved. It doesn't take long to figure out that your life isn't worth that much to her. It's her dialogue that makes the game great. And just messing around with the portal gun. It's pretty short though, so if you're gonna buy Portal 2 then I'd just borrow the first one to save yourself money.
I like the puzzle where you just shoot a portal down below, jump down, come back up waaaay high, shoot a portal into the next platform and repeat until your jumps get higher and higher xD