As a relative newbie to DE shaving i've found the sharper blades which most here seem to like (irriduim supers, feathers, etc.) irritate my skin too much, i wholly accept that this is down to shoddy technique.
There are also a number of blunter blades which i find tug and catch far too much (lord, treet, etc.) these require 4 or more passes to get a decent shave and so also irritate my skin, i'm less willing to accept that this is shoddy technique but it could be.
Best for me have been shop brand personna's and Astra super platinums with 7 o'clock platinums coming in a little after and then a bunch of others which will do the job before falling into one of the above categories.
I'm hoping that in the near future I'll be able to expand my collection of razors and start experimenting with different blades for different passes. i.e. 1st pass sharp, 2nd pass current favourite 3rd / buffing pass - blunt seems logical but who knows...