it depends what baseband you are on, ie DI01, DJ05 or DL09. even after you figure that out, it's all subjective... but JT makes pretty good kernels, and I think adrynelyn has a good one out.
If you have DJ05, I use Stupid Fast 12.19 which works well for me. It also allows you to change boot and shutdown animations. If you are using DL09 I can not help you since I reverted back to DJ05 after an hour of DL09 flashed from here via Odin.
DJ05 kernels work with DL09. Best is just going to be an opinion. I personally am a fan of StupidFast v1.54. I have used JT's as well which also worked very well. You can flash them on top of each other so I would just say start trying and a pick your own favorite. That's half the fun anyway.