Clearly Kolyada's 3Lz is the biggest https://youtu.be/Px-6NRKG4lg?t=28m35s but it's not my personal favourite because it can go a little bit off axis. In every other respect it is marvelous.
When I watched it live I thought for a moment he doubled - the height was so huge that 3 rotations were sort of lost there - he had a room for another two I think. As Julia commented once 'he launches like a rocket into space'
Answer is pretty obvious for current active men skaters - Jin Boyang for 4Lz. Han Yan and Kolyada both have very very good lutz as well although I give better weight to the former as his toe pick and little pre-rotation looks more impressive. If we go back historically, Tatsuki Machida and Brian Boitano stand out as having awesome lutzes technically.
Rippon - based on (the most interesting/good) position in the air, if he decides not to be active anymore, than Kolyada (based on the best height and distance)
boyang, absolutely perfect technique- italian eurosport described it best. kolyada and others are good as well but not quite as flawless with the toepick and position.
Thanks for all the contributions! Polls are now up and ready! Remember, these are for active competitive skaters. Vote on the skater who has the best technique for the triple Lutz.
Kolyada has absolutely perfect technique on Lutz and his 3Lutz is also the biggest Lutz out of all men. Of course, he fails the 4Lutz very often but that's not an issue when discussing the 3Lutz.
Kolyada's Lutz, you tape it and send it among the Vitruvian Man and etc. to space, in case there is an extraterrestrial life to give them know what Lutz is.