The Best IML Sub that you have used

[Yous]

For me, I can't choose.  There are several that have been awesome and life changing for me.

AM 1 through 6 made a huge impact on my life.
SM got me out of my social anxiety and allowed me to start socializing.
MIR has literally saved my life at least three times.
USLM pulled me through some really rough times I would have not been able to make it through otherwise.
LTU5 made a world of difference for me personally, and as a result of how it worked for my girlfriend.
UMS has changed a lot of things in my life for the better.
DMSI 3.1 actually got me my girlfriend, which changed my life forever.
BAMM pushed me through loads of fears to get to where I am now.  I stopped using it because I had to use MIR for an extended time at one point, and then I realized that I was not advancing anymore because fear had stopped me.
And there are others I can't even remember.

A world of diffence in LTU 5? Could you explain a bit more please?

LTU5 changed my life for the better in a lot of ways.  It dropped my stress levels like a rock, gave me a lot more hope, improved my emotional baseline level, gave me the strength to keep going under the challenges I was facing, made my relationship with my girlfriend better not only by reducing our stress but by helping her deal with several challenges she was facing at the same time (which is why LTU 4/5 got made in the first place), improved my relationship with my family, pulled some old friends back into my life, made my sleep significantly better, and more I can't remember off the top of my head.

Thanks