It seems clear that #4 is the winner here. No surprise, this is the Axe (Plexi 2). It sounds and feels incomparably better than the others, no doubt for me and for some of you.
#1 was a great surprise for me, though, it is a TC Vintage Dual Distortion, a nice distortion pedal, now discontinued. It sounds quite good IMHO, and some of you seem to agree.
#5 is an even cheaper pedal, a Boss SD-1, made in Taiwan, nothing special about it. Yes, it sounds a bit muffled, but not too bad considering its price.
#2 is a Digitech Jimi Hendrix Experience pedal, I dialed off reverb and cab emulation, nothing special about it either.
#3 is a Pod HD500, it can sound much better than this, but one of the premises of this little experiment was to use almost all default parameters, I didn't spend more than one minute making each sound. It sounds quite harsh, and it takes some more effort to get a pleasing sound from it.
All of these machines can easily sound much better. Fractal Axe and Pod HD500 have a greater margin for improvement than the little pedals, and of course, the Axe is the only one which allows the use of external IRs.
Thank you everyone for taking your time to listening and answering. I hope you have had some fun too.
No real amps were harmed in the making of this little experiment.