That's a tough one! I love Peter Pan for the nostalgia and the childhood memories I have riding it.
POTC reminds me of fine times as a kid visiting Disney, and who doesn't love Captain Jack?
BTMRR is a favorite because DD15 and I don't like thrill rides, so this is as wild and crazy as we get. Great memories of riding it repeatedly in the back row, at night during the fireworks, in 2007.
Mickey's Philharmagic takes my breath away each time I see it, it's just so "Disney".
And as much as I HATE haunted mansions (got lost in one as a kid, traumatized for life), I have to say the HM ride is absolutely amazing!! I never fail to notice something new and it's just done so well (even if it took me till I was 35 to get up the nerve to try it for the first time, and even that was after I watched it on YouTube to make sure I wasn't going to freak out!).