There are many, many, many different ways you can go surveying the multifarious creations of one-man aural juggernaut Aphex Twin. You can go as abstract, ambient, aggressive, or tuneful as you want. All you need is time. Just press play.
As for my favorite thing I've heard from this electro-Mahler, I am comfortable saying "Finger Bib."
It's not as challenging as the ambient works, not as edgy as the buzzsaw Come to Daddy period. Instead it's about as "pop" as you can get out of Aphex Twin, with honest, finished melodies in a cheeky pentatonic scale. The meter breaks up as the piece develops but doesn't fly too far out there, and it all gives way back to the happy main theme anyway. It's far less beat heavy than many Aphex Twin pieces, which is usually kind of a calling card, but I could care less.
Of all the excellent sounds deployed, the intensely oscillating sound of the lead synth is the real brain smiler here. There is so much innocence in its sound quality to go along with the airiness of the melody's quick phrasing. Also listen to the dissonances in the accompanying chord pattern, putting even his most accessible stuff off-kilter.
Of the hours of worthy challenges Aphex Twin has painstakingly designed over a distinctive career, this little chamber piece is one I always have time for.