Blades come in all forms and sizes… uhm, no. The beauty of traditional DE wetshaving is that blades do NOT differer in form or size – they are all the same as far as physical dimensions go. They are conceptually different from cartridge blades in that regard; while each different cartridge requires it’s own proprietary razor (with a couple of honourable exceptions), all DE blades fits in all DE razors.
That does not mean that all DE blades are created equal – far from it. The differences in the actual blade might be minute, but the difference in opinion can make you wonder if people are even talking about the same blade. And just to make life even more interesting a blade can behave radically different in tow different razors.
Some things almost everyone can agree upon: Feather blades are really, really sharp, carbon steel blades rust more easily, and mind your fingertips.
There is no such thing as “the best blade”, but there is such a thing as “the blade that works best for you in your razor”. After you have honed your technique somewhat and can get a consistently good shave using a DE razor, you might/could/should get hold of a sampler pack or ten. Most online shaving suppliers offers them, either as a selection of popular blades or as a selection of blades from a given country, region or manufacturer. The basic idea is the same; try the various blades and see which one works best for you. It could be that the blade you used previously works best – it could be that you can never go back to that first blade again.
It’s all part of the journey of discovery. Who knows where you might end up?