Do a top 5, or 10 if you want. Rank them accordingly. Personally I put Pirates of the Caribbean (Disneyland version) as #1. Here is the list:
#1 Pirates of the Caribbean (Disneyland) - Even before riding the Disneyland version I thought the WDW version was the best ride ever. Disneyland's version is clearly better and longer which is the type of ride you want to be longer. This is a ride that has everything. Nostalgia, attention to detail, top notch theming, and a sense of escapism. I was skeptical about how they could combine the Blue Bayou with the beginning of the ride but they do it rather well. They theme it well with the New Orleans swamp atmosphere before transitioning into the Caribbean. Unbelievable ride, I've loved it more than anything since I was 10 years old. At 32 it is still my favourite. We rode it 4 times on our Disneyland trip. I get taken right back to that ride whenever I hear the "Yo Ho" Pirates song.
#2 Haunted Mansion (WDW) - The one time we were in Disneyland it just so happened to be the exact time it was closed for the Halloween makeover transition. That's a shame, because I love everything about it in WDW. From the reports I have been told the WDW version isn't any worse. I love the tombstones out front, the stretching room and the overall mood of the ride. I almost wish I could just get out and explore the place. Few rides give you that Disney feeling like this one.
#3 Splash Mountain (WDW) - I think the WDW version is noticeably superior. It's longer and better paced. Again, this is a ride that has everything in it. A nice drop at the end, you get a little wet, the music is great, the characters and the story is great and in the WDW version the hidden mickeys are fun to find.
#4 Tower of Terror (either version) - Maybe the WDW was a tad better because there is more time before the drops but either way this is an attraction that takes you right into another era. It takes you into into 1930s Hollywood in the Golden age. I have always felt that a drop in pitch black is scarier then the run of the mill ones in broad daylight in a normal theme park. The music, Rod Sterling's commentary and the fact that the scariest part is the anticipation makes this the attraction we've all come to love.
#5 Radiator Springs Raceway - We saved some time and went in the singles line. We still ended up in the same car. It was totally worth the wait, even 30 minutes. It's a great all around ride and it is themed wonderfully too. Definitely a better attraction than Test Track at Epcot.
#6 Small World - Doesn't matter the version. Both are great. I like the added characters in Disneyland's version. I know that irritated some people but it isn't intrusive and they blend it in there well. I might be one of the few people who never get annoyed with that song. This is the first attraction I ever went on at WDW when I was 10 and it has always had a special bond with me.
#7 Indiana Jones - Better than Dinosaur at Animal Kingdom which is a ride it often gets compared to. The theming is done too well here for me not to put it on the list.
#8 E.T. - Yeah I have to throw in at least one Universal ride. E.T. is mind blowing for me. If you watched the movie it is impossible to not feel connected with it on this ride. It is total immersion that is Disneyesque. Very touching too. You don't think you're on a theme park ride which is a commentary on how great an attraction actually is.
#9 Country Bear Jamboree - One thing I didn't like is how they took it out of Disneyland. I wish it was in there because I love it in WDW and hope it always stays (they just did a tune up of it). It has this charm to it that only Disney can duplicate. The songs and the characters are lovable. I look at the space around Winnie in Disneyland and can't understand how they couldn't have still kept the Bears around and added Winnie too.
#10 Jurassic River Adventure - Again, another Universal ride that captures the Disneyesque way of transporting you into that movie and feeling a part of it. The T-Rex at the end gets me every time. I'm a big fan of the movies, especially the original one, so it really hits home with me.
The funny thing is there are 8 Disney rides on here and 2 Universal. I am a big rollercoaster junkie and yet when you compare them to things like Pirates you always favour Pirates first and foremost. It is the all around feeling and atmosphere of a ride that keeps me coming back and forces me to place them on this list even over other rides that surpass them in the thrill department. Thrills are certainly not everything when it comes to attractions, and my list proves it.