I'm in agreement here. For a good long while Lateralus was my favorite song, but I kind of grew out of it a little bit and at this moment right now it seems that I actually prefer The Grudge. My opinion is very likely to change again over time, but for now I've got to give Lateralus the vote.Like Master of Puppets and Hallowed, Lateralus started as a favourite and slowly got buried under other songs as I listened to Tool more and more. These songs leave in me the semi-stale taste, like a fraction of what you got the first time.
This also happened to The Grudge, but I already found it's charm again, and I will stay true to my current opinions.