I'd have to say second
Even though the part 1 sounds a lot more hardcore and jumpy, after a while all you seem to hear is the wah, wah of the synths coming through the side chain and it gets a little ordinary especially in the last part of it where the kick cuts out but the sidechain effect is still going on.
The second part however, since it is not sidechained as much, the whole mood of the piece seems a lot more high energy and fast paced to me.
Probably because more of the synths are getting through and you can enjoy more of the small details which are otherwise cut out by the sidechaining.
Personally, so me part II seems to have a more trancy feeling to it than part I, and I can imagine listening to it for ages without getting bored of the song.
Hope this helps out man
peace~