Probably Floral Field, partly because I think it does its job really well of A) matching the stage gameplay, and B) setting up the melody for the rest of the stages to reference. Also, I feel like I'm at my best when I'm dictating the melody and chord progression, and I think the way I extended on the original tune was very effective and more graceful than most of my other remakes. Egg Satellite was similarly an ambitious remake, but I think in attempting to mesh everything into the stage's natural time limit, the tune's progression ends up stumbling on itself a little bit.